Mark W. Thompson, Fairport: Passed away in his home on Sunday, September 12, 2026, in his 66th year. Loving husband of his late wife, Dianne; beloved and devoted father of Chris and Colleen and their partners, Julia Perriello and Dave McGregor; caring partner of Linda Eaton; adoring grandfather of Angela. He is survived by his parents, David and Louise Thompson (Harrington), and siblings, Sue (Primmer), Paul, Bill, and Kate (Pugh). He had recently retired from his career as a respected electrical engineer at Harris Corporation, where he was named a Harris Fellow. Mark was a passionate cyclist, runner, hiker, and lifelong lover of radio. He was a lover of adventure and challenging himself. Having always given himself to those he cared for, he will be deeply missed.
Friends may call at the Richard H. Keenan Funeral Home (Egypt Location), 7501 Pittsford Palmyra Rd., Fairport, Thursday September 24, 2026 from 3 to 6 p.m. Funeral Mass Friday September 25, 2026 at 9:30 a.m. at Church of the Assumption, 20 East Avenue .
In lieu of flowers, donations may be made to the St. Joseph’s Neighborhood Center, Rochester.
86 responses to “Thompson, Mark W.”
Wish I could have known him better. He sounds amazing.
Mark was one of, if not the best engineer I worked for at Harris. As a technician he always took the time to teach me what he was doing and why.I learned so much from him. My heart goes out to his family.
I’m so sad to read this! Mark was an amazing mentor, engineer and person. A genuine pleasure to work with and learn from. I wouldn’t be the engineer I am today without all the knowledge I gained from getting to learn from Mark.
My deepest condolences to his family and friends. Rest in peace, Mark!
Mark was always so upbeat, positive, and ever so helpful to others…and he was as sharp of an engineer I have ever known. Every few months, I would bump into Mark at Wegman’s and he always wanted to chat and ask how I was doing…always positive…such a gentleman. The world is a little less upbeat without Mark. My heart goes out to his family and friends.
I am shocked by this news. Mark was a great guy to work with, very patient and helpful. He will be missed.
Condolences to Mark’s family.
The news of Mark’s early passing was truly heartbreaking. He was an outstanding friend and mentor to so many people. His energy and thirst for life were unmatched by anyone I know. He loved his Engineering profession and was always eager to share his knowledge with anyone looking to learn. I will miss him greatly!
I worked with Mark on several occasions and found him to be the kindest person, always looking for ways to help. He will be sorely missed.
Thoughts and prayers for his family in this difficult time.
I started my career with Mark quite some time ago, his passing is quite a shock. He was so young. Mark was one of the best people I ever worked with. My condolences to his family.
I worked for Mark early in my career and he was a mentor and friend. He taught me a lot that I used throughout my career. Condolences to his family. He will certainly be missed.
Mark was a good man and Engineer. Very sad news! My prayers go out to his family.
Mark was a mentor to so many in his field including myself; this is an immeasurable loss for so many reasons. His legacy lives across the countless lives he has shaped and he will always be one of the greats.
Mark was a tremendous human and an amazingly talented engineer. He will be missed.
Mark was the best combination of really smart and really nice. A humble leader,a great engineer, a great mentor to many; most of all, a great person. Most definitely will be missed.
Mark was a talented engineer and great person. It was an honor working with him. My condolences to his family and all who loved him.
Mark always had the best attitude in and out of work. This is really sad news. Prayers go out to his family and all his friends 🙏🏻🙏🏻🙏🏻🙏🏻
Mark was a fantastic human being and a great colleague. His brilliance was only overshadowed by his humble demeanor. Will be missed
In 30 years of engineering I cant think of someone kinder and more willing to help and more importantly teach. Devastating news and deepest condolences to his family.
I lack the words to adequately describe Mark as he should be remembered. He was one of the best, hardest working and most patient engineers I ever met. But I most admired his humility. I’m so blessed to have known him and deeply saddened by his passing
I lack the words to adequately describe Mark as he should be remembered. He was one of the best, hardest working and most patient engineers I ever met. But I most admired his humility. I’m so blessed to have known him and deeply saddened by his passing
Amazing guy. I worked with and for Mark at Harris. Everything stated by all the Harris people is 100% accurate.
I would only be repeating everything that everyone else has already accurately stated.
Proud and blessed to have known him.
Such a sad loss of a wonderful, kind, wicked smart and humble person. A very rare combination of traits that touched so many peoples careers in different roles including operations, engineering, supply chain, product engineering, etc. My thoughts and prayers to all he knew him, and were blessed to work with him.
I will remember his laugh and smile, his grace under pressure, his work ethic on the job and on the ice. His seemingly limitless engineering talents were always shared with humility and for the benefit of those he worked with. All the comments are a testament to the incredible impact he had on all of us. Thank you Mark.
Truly shocked by Mark’s passing. He’s the only one I knew who ran and biked the Seneca 7 relay. I echo the thoughts of talented engineer and super nice guy. He will be missed.
Mark was a brilliant engineer, a cherished colleague, and a great human being. I will always cherish our time working together. May God bless you, Mark.
Mark was one of the brightest engineers I ever had the opportunity to work with at Harris – he had a wonderful sense of humor and always ready to take time to listen and bring insight to your tough technical problems. My condolences to those Mark has left behind.
Mark was truly an incredible person and an outstanding engineer. I feel very fortunate to have had the opportunity to know him over the years. He was consistently kind, thoughtful, and generous with everyone.
His talent, dedication, and contributions were remarkable, and I’m not sure we will ever fully appreciate how much he gave to those who had the privilege of working with him. Mark was the kind of person people enjoyed being around and will remember long after the projects have faded.
I will always remember him and may he rest in peace
I am shocked! First met Mark in the early 90’s playing hockey together at Thomas Creek. In 2001 I joined Harris and had the pleasure of working with him. We often crossed paths out in Fairport village. Our last encounter was maybe a month ago. My deepest sympathies to his family. An exceptional person!
So saddened by Mark’s loss. He was such an engaging, warm, and brilliant person to work with. His love for teaching others was always apparent. Thoughts and prayers with his family and friends.
I’m deeply saddened to hear of Mark’s passing.
For the 25 years I had the privilege of working alongside him, I knew him as an exceptional engineer whose intelligence, skill, and insight were matched only by his humility and kindness.
It is especially shocking to hear of the loss of someone who was so fit, active, and full of life.
Mark will be remembered not only for his remarkable professional contributions, but also for the warmth, modesty, and friendship he brought to those who knew him.
My sincerest condolences to his family at this time of great loss.
So saddened to hear of Mark’s passing. Mark was an exceptional RF Engineer (one of the absolute best), a great colleague, a kind mentor to many, and someone whose work and guidance have left a lasting mark on many. My deepest condolences to his friends and family.
He was an outstanding Engineer and terrific fellow, and a joy to work with. He will be missed. My prayers go out to his family and to Mark.
I had so much respect for Mark. Besides being incredibly intelligent, he was such a genuine and nice person. I would feel bad taking any time away from his more important tasks to ask a question, but he was always so generous with providing advice and his time to help others learn and grow, and he had a curious mind and always wanted to continue to learn as well. His legacy is enormous for so many of us at Harris. I am very sad to hear of his passing and am thinking of his family.
As a L3Harris fellow, Mark was often brought in to help solve difficult, business critical problems. I had the pleasure of working with him on some of those issues. He was always respectful, encouraging and made those stressful issues easier to work through. It was great to work with Mark for those brief times. My deepest sympathies go out to his close friends and family.
Professor Thompson was an incredible person and my professor at RIT. He always encouraged me to aim high and inspired me to pursue a career at L3Harris. It was truly an honor to have been one of his students. Although I never had the chance to see him at L3Harris, I would often notice his picture on the wall and proudly say, “That’s my professor.” I’m deeply saddened that he is no longer with us, but his spirit and impact will always live on.
Mark was my first circuits professor at RIT. I came into his class with no background in EE, but he created a warm and welcoming environment during an otherwise intimidating time.
His kindness, patience, and depth of knowledge were unmatched. He assisted me on his own time, even when I wasn’t enrolled in his classes. I’m certain he had the same impact on countless other students throughout his career. He will be deeply missed.
Mark was an amazing adjunct at RIT. The students loved him and he made an extraordinary effort to make sure the students learned all the material in his classes. This comes as a shock. He will be missed very much at RIT.
I have known Mark for 26 years, and it is difficult to find the words to express how deeply saddened I am by his passing.
Mark was truly one of those rare people who made a lasting impression on everyone fortunate enough to know him. He was incredibly intelligent and talented, but what I will remember most is his kindness, humility, generosity, and genuine concern for others. No matter how busy he was, Mark always seemed to have time to listen, share his knowledge, or lend a helping hand. His passing is a tremendous loss, but the positive impact Mark had on so many lives will continue through the people he helped, mentored, encouraged, and inspired.
My deepest condolences go to his family and all those who loved him. May you find comfort in knowing how many lives Mark touched and how fondly he will be remembered.
Rest in peace, Mark. You will be deeply missed, but never forgotten.
It was a privilege knowing Mark and working with him for 30+ years. A really smart guy with a great personality and a never ending smile, he will be missed by many! My condolences to his loved ones.
God must have needed a great scientist. That is the only reason I can think that he took Mark so soon. Mark was a sponge that had a thirst for knowledge. He has multiple Master’s degrees , so many that I stopped keeping track. Mark was in the Master’s program that I took back in 2004-2007. He had already had a masters, and I believe he mastered in statistics after that. He was not only knowledgeable and smart, but he was a hard worker and didn’t take short cuts to solve problems, which usually led to faster solutions. He was just as demanding of himself in his personal life. Humanity will miss him a great deal. RIP Mark
My thoughts and prayers go out to Mark’s family. I had the honor to work alongside Mark throughout my career as well as classmates getting our Masters degree through FIT. He is one of the smartest and humble engineers I have ever met. He will be missed.
It was an honor and privilege to have worked Mark on a variety of projects over a 22 year period. He was a role model (for me) as both an engineer and a person. Mark – as stated more elegantly on other replies – you will be sorely missed – but never forgotten.
Mark was my DSP professor at RIT and quickly became one of my favorites. He was incredibly kind, patient, and brilliant. I remember my team struggling with a final project problem, and even after his office hours ended, he made time for a 1 on 1 Zoom meeting to walk us through a solution. He never hesitated to go the extra mile for his students.
He brought so much joy and clarity to the classroom and helped countless students along the way. I’m proud to have known him as a professor. He will be deeply missed.
My condolences to Mark’s family in this difficult time. Mark was a great engineer and mentor but an even better person. It was a privilege to have known and worked with Mark. He will be missed.
Prayers for the family and friends of this exceptional Engineer and colleague. I had the pleasure of working with Mark as an Engineer new to L3Harris and he was a phenomenal man to learn from and work alongside. As a fellow colleague from Product Management once said of Mark, he could design his own spaceship to land on the moon if we wanted to, there seemed to be no limit to his technical abilities. The family will hopefully find comfort in the fact that his contributions to L3Harris product capabilities doubtless has saved the lives of millions of soldiers and first responders. Mark’s technical contributions to L3Harris reached every area of the Communication Systems business (and beyond) and he will be missed.
I worked with him closely for about six months. He was a genius person and an engaging mentor. I will remember his accompany. May the God bless his departed soul.
Mark will be remembered by many as engineer, teacher, and all around great human being. No questions were ever beneath him, and his patience to help anyone was beyond compare. He always made time. He also slowed down to smile and wave when he rode past my house, and I will miss that too.
Mark’s enormously positive attitude always improved those who worked around him. He was a much-needed bright spot here at Harris among the many technical challenges we faced over the years. To Mark’s family: thanks for sharing him with us.
To Marks family, I’m sorry for your loss. Our prayers are with you during this time of mourning. I’m happy to have known Mark. He helped me in a great time of need and I will remember him as a gracious person who cared for others. Jeff C
I worked with Mark for over 30 years and he was the nicest and best engineer. He always had a smile and was a very positive person. He was amazing to work with and shared his knowledge. My condolences to his family. Prayers to you all!
I first met Mark in my DSP class at RIT. He was a great professor and mentor, but he also played an important part in helping me graduate. Soon after we were both at L3Harris, running into each other in the labs and he always checked in asking how my projects were going. Truly an inspiring, genuine person. You will be missed, my condolences to the Thompson family.
Our thoughts and love go to your family at this sad time.
May Mark’s memory be a blessing to you all.
So very sad to hear about Mark‘s too early passing.
I grew up with him on Longview Terrace in Williamstown and it was a wonderful childhood for all of us. Camping on Cape Cod, family bbqs & life on Longview riding our bikes from noon to dusk. We went to school & graduated from MGRHS where Sparky excelled at hockey & x-country. He was a great guy throughout, a gentle soul and will be greatly missed.
My thoughts, memories of him and the wonderful Thompson family are with all of you.
Peace & love from all of us at 99 Longview-
Dede & sibs
Everytime I saw Mark in the hallways of RF Comm, I’d say “Fuzzy Logic.” Mark was a great guy, always smiling and friendly. He will be missed.
I am so sorry to hear about Mark’s passing. He was such a great guy – smart, humble, always willing to help people. He will be truly missed. My deepest condolences to his family.
Mark was an amazing engineer but more importantly an amazing human being. Mark was the kind of person everyone should try to emulate. His humbleness and willingness to help can’t be overstated. He will be missed. My condolences to his family.
So saddened to hear of Mark’s passing. He was a brilliant engineer and was always willing to listen and help with tough technical problems. He will be missed. My thoughts and prayers go out to Mark’s family.
My sincere condolences to all of Marks family and friends.
Sincerely,
Paul’s camping neighbor Cindy
I was truly saddened to hear the news of Mark. Yes he was a great engineer and Harris Fellow and a great mentor – but more importantly he was an amazing kind hearted man. My condolences to your family.
Graduated from high school with Mark’s older sister Sue.
Played hockey with both Mark & his older brother Paul.
Learned about his passing thru my older sister, a classmate of Paul’s
Lots of wonderful memories on & off the ice growing up in a small New England town with great families like the Thompsons.
My condolences to everyone who knew & loved Mark.
Mark was a great colleague, mentor and friend. His go to tool in engineering was always MATLAB and he could solve almost any problem with it.
I will miss him dearly and send my condolences to the Thompson family and those he left behind.
For Mark’s children and family and closest friends…… I am so sorry for your loss. Mark is a fantastic human and we are all so grateful that we got to share in him. Thank you for that 🙂 I’ve been at Harris for almost 34 years now, and Mark is one of tiny group of people who are touchstone points for me. My life and my career are better for having known Mark. That’s a fact. How do you thank someone for that? His joy in life and optimism….. man did that resonate with me. Thank you Mark, I’m sorry you’ve left us. -Bob
I knew him as professor Thompson, and he was the nicest, honest and thoughtful person I’ve met. He always liked to help others even outside of academia. I send my wishes to his family and hope they know many people viewed him as I did.
Mark had the rare combination of an outstanding engineer and a truly nice human being. I never heard a negative statement from him in the years we worked together. He never talked “down” to anyone and had the patience of a saint. The human race has truly lost one of the good ones.
I first met Mark years ago at RPI. We both graduated and went on to long careers at Harris. Before Mark retired I was his supervisor. It was the easiest role I ever had. Mark knew what the big problems were and just fixed them. I was with Mark when he was recognized as a Sr Fellow. Somehow word had gotten out that Mark liked RVs. Instead of driving ourselves from the Hotel to Headquarters a big fancy RV pulled up and transported Mark, Dianne, my wife and myself to the event. I always enjoyed it when Mark and I got to work together on a good technical task. As you can see from these posts Mark was well respected and loved. My condolences to his family.
Mark will be so sorely missed. He was such a wonderful person. He was brilliant but humble and selfless. His technical accomplishments and contributions were many and had such profound impact. Mark could do anything and he brought out the best in everyone who had pleasure to work with him. Thank you to Mark’s family for sharing him with all the rest of us.
Mark Thompson contributions to life and work has positively influenced and impacted so many at RF Comms/Harris/L3Harris in such a positive personal and positive professional way.Truly a model person to know. He was an inspiration to many even if you never had an opportunity to work with him on the multitude of Harris products.
I repeat everything said by others. I worked for Mark for few years while in secure products. One of the best supervisors I worked for in my 20 years at RF. He also was an adjunct professor at RIT where I’ve worked since leaving RF
I’ll miss him.
I am deeply saddened to hear of Mark’s passing…my heart and love goes out to all of Mark’s family.
I met Mark in 2002. Never had the pleasure to work directly with him. When I asked him a question he always took the time to be sure I was ok with his answers.
I think I talked to him at the hamfest at the Log Cabin restaurant last year or the year before.
My sincere condolences to all of Marks family, friends and Colleagues.
Mark was my friend, neighbor, co-worker, and fellow cycling enthusiast. He was smart, kind, humble, and just a great human being. What a terrible loss. He will be greatly missed. My deepest condolences to his family.
My heartfelt condolences to Mark’s family and everyone who loved him. Although the time i had the opportunity to know Mark was short, it didn’t take long to see what kind of person he was. He was very likable, genuine, and had a caring heart that made it easy to become attached to him. His presence touched people, and I know he will be deeply missed. May his family and loved ones find comfort in the memories they shared with him.
Mark was not just a colleague, he was a very good friend. He will be deeply missed. The time I spent learning from Mark or just sitting with him and talking, was priceless. He was one of a kind. His character and wit were simply amazing. Mark always told me if I ever needed to wow a crowd, just get up and start talking about third order intercept points. Mark is probably up there explaining that to Chuck Norris as we speak. He always knew how to make people laugh. My condolences go out to his family and friends.
Mark was a wonderful guy, and a great Engineer. He will be sorely missed both for his humanity and his deep knowledge of radio. I always enjoyed consulting with Mark.
My older brother Mark is one of those rare people who somehow managed to be kind, gentle, incredibly intelligent, and still deliver some of the absolute best or worst dad jokes known to mankind. He was always available when I needed him—for advice, a helping hand, or a laugh. I called him up to help me build a chemistry experiment for some of my students. He was patient and gracious with his time. He was competitive in pretty much everything, which makes sense considering he was a runner, cyclist, hiker, snowboarder, wakeboarder and apparently believed sitting still was a waste of perfectly good daylight. But beyond all the miles, races, adventures, and terrible dad jokes, Mark was truly one of my best friends. He was the kind of brother you know you can count on, no matter what. And then there’s Mark and my Dad—two peas in a pod, cut from the same cloth. He loved working on and just talking radio nerd stuff with our dad. I’m incredibly lucky to call Mark my big brother. I can only justify his passing by thinking that his work on earth was done. I guess he felt I was ready to step into his shoes to help our parents move into the next phase of their lives. Helping family was a privilege to Mark. He said that often. All of us will miss him terribly.
Mark was an incredible person, so kind, humble and extremely talented. Always quick to step in with a smile on his face and soft words. Mark was always able to resolve the most challenging of issues while mentoring and bringing fellowship to those he interacted with. He has left and indelible mark on both the people and projects he touched. Gone way too soon. Rest easy Mark, your work here on earth may be done but your legacy will live on in the many hearts and souls you have touched. My deepest condolences to his family.
I am still shocked and saddened to hear of Mark’s passing. Mark was a wonderful person. I had the privilege of knowing him throughout our entire time working together at Harris Corp. I’ll always remember when he and Dianne hosted our whole project team and our families at their cottage on Owasco Lake. Mark’s smile and laugh will stay with me forever. I am proud to call him my friend, and my thoughts and prayers are with his family.
I first met Mark calling on Harris over 20 years ago. I was just learning active components and didn’t totally know what I was doing yet. Mark was so kind, and patient in meetings with me, he would not just take time for me but he would also teach me. I am very sad to hear about his far too soon passing, my condolences to his family. He really was one of a kind, the rare mixture of brilliance and at the same time humility, kindness and grace..
I am shocked and saddened by the news of Mark’s passing. Through Harris and then L3Harris, I had the good fortune of knowing Mark for over 40 years. He was a great guy and one of the smartest people that I ever worked with. I was amazed by the depth and breadth of his technical knowledge, and I always enjoyed his sense of humor. My deepest condolences to Mark’s family.
We were all incredibly gutted to hear of Mark’s sudden passing. Mark was a prince. He set the bar for all of us as an engineer and as a person. He was the smartest guy in any room, yet was always humble and approachable. His character and integrity were unimpeachable and respected even more than his matchless capabilities and contributions. He leaves gigantic shoes to fill and will be missed by countless lives he bettered at multitudes of venues where he served throughout his life.
I have had the pleasure of working with mark for over 30 years. he was a standout as a superb engineer, mentor, and caring person. he always greeted folks with a warm smile and welcoming attitude. He was a passionate person in his life and work, and for those around him. He left us way too soon, but will be long remembered. thanks for your friendship mark.
I am heartbroken to hear of Mark’s passing. As all who have commented previously, Mark was truly one of the kindest and most generous people with his time and wisdom. In working through some difficult, high pressure problems at Harris, I cannot recall a single instance of Mark being anything but pleasant. He was extraordinarily smart and curious. There was no problem you could present to Mark without having confidence he could solve it. It was truly an honor knowing Mark.
It is very sad to hear of Mark’s passing. We started our careers together 44 years ago at Harris under George Helm. Mark was always a smart, positive, driven person and an excellent engineer. He will be remembered as a really nice guy. I offer my sincere condolences to family, friends and colleagues. Mark will be missed.
Ruth, Jane and I only knew Mark for a period of weeks, but his kindness, eagerness to help and genuine concern endeared him to us quickly. Words fail to describe the impression he made on us and our prayers and sincere sympathies go out to his family. Dave and Louise, we will not soon forget him.
I just learned of Mark’s passing today. I am shocked and saddened. Mark was truly a special person, he was a brilliant engineer but treated everyone with humility and respect. This summer we were comparing notes about retirement and how to approach establishing a new normal. He was looking forward to his next chapter in life. My heart goes out to his family!
So sorry to hear this news. Rest in Peace Mark. It was a pleasure working and having your friendship. Your son Chris is a really wonderful smart man and a wonderful husband to my 2nd cousin Julia. My prayers and condolences to your family.