Dennis “Sully” G. Sullivan Obituary: Menomonee Falls, WI Man Dies at 72 After Battle With Esophageal Cancer

Dennis “Sully” G. Sullivan Obituary MENOMONEE FALLS, Wis. — Dennis “Sully” G. Sullivan, a longtime Wisconsin resident whose life revolved around family, sports, music and hard work, died Tuesday, August 18, 2026, following a two-year battle with esophageal cancer. He was 72.

Known affectionately as “Sully,” Dennis leaves behind a family that remembers him as a devoted husband, proud father and grandfather, supportive brother and loyal friend. His larger-than-life personality, humor and unmistakable presence made him someone people remembered long after meeting him.

From Milwaukee Athlete to Wisconsin Badger

Dennis was born November 28, 1953, in Milwaukee to Bob and Cathy Sullivan. Growing up in Wisconsin helped shape both his lifelong passion for sports and the work ethic that would follow him throughout adulthood.

He graduated from James Madison High School in 1972, where athletics became an important part of his younger years.

Dennis competed in basketball, football and baseball, but it was behind the plate as a catcher that he particularly distinguished himself. His baseball abilities eventually earned him a scholarship to the University of Wisconsin-Madison, marking an important accomplishment in his athletic journey.

His love of competition never disappeared. Even after his own playing years were behind him, sports remained deeply woven into his life.

Dennis Sullivan Cause of Death

Dennis “Sully” Sullivan died following a courageous two-year battle with esophageal cancer.

His death on August 18 came at age 72, ending a difficult health journey during which his family remained an important source of love and support.

While cancer became part of the final chapter of Dennis’ life, his loved ones are remembering the much larger story that came before it, including decades devoted to his family, career, music and the activities that brought him happiness.

Nearly Four Decades of Hard Work

Professionally, Dennis spent almost 40 years working as a welder.

It was a career that reflected the strong work ethic he developed early in life. He took pride in working hard and building a comfortable life for the people who mattered most to him.

Dennis and his wife, Pauline, made their home in Menomonee Falls for 38 years while raising their family. About five years before his death, they began another chapter together in Germantown.

Home was something Dennis took seriously. He spent considerable time caring for his yard and gardens, creating spaces where his family could feel comfortable and welcome.

Music, Drums and The Flunk Band

Sports were not Dennis’ only passion. Music also occupied a special place in his life.

For more than a decade, he played drums with The Flunk Band, performing rock-and-roll music from the 1960s.

Being behind the drum kit allowed Dennis to enjoy the music of his youth in a different way. That enthusiasm remained with him throughout his life, and he shared his appreciation for music with his children and grandchildren.

Between music and sports, Dennis found plenty of opportunities to enjoy friendly competition, conversation and laughter. He remained an enthusiastic supporter of Wisconsin sports teams and also enjoyed fantasy football and the good-natured banter that came with it.

Family Was at the Center of Sully’s Life

Of all Dennis’ accomplishments and interests, his family remained his greatest source of pride.

He and Pauline Sullivan were married for 45 years, building a life that eventually grew to include three daughters and seven grandchildren.

Dennis was the father of Kelsey (Steve) Sperl, Deanna (Joseph) Orlofski and Mallary (Andrew) Sedlmeier.

His grandchildren, Isla, Skylar and Sully Sperl; Abram and Hank Orlofski; and Luca and Laney Sedlmeier, knew him lovingly as “Papa.”

Being Papa was a role Dennis embraced completely.

If one of his children or grandchildren had a soccer game, baseball game, basketball event, dance recital, school play or another important activity, Dennis wanted to be there.

His support was not quiet or distant. He showed up, cheered and made sure his family understood how proud he was of them.

Those moments became especially meaningful during retirement, when spending time with his loved ones brought him some of his greatest happiness.

Remembering a Larger-Than-Life Personality

Dennis’ personality was another reason his absence will be strongly felt.

Friends remember his humor and his ability to enjoy conversation and friendly banter, particularly when sports were involved. His connection to local athletics also brought him into contact with many people throughout the Menomonee Falls community.

He is survived by his siblings, Gary (Lora) Sullivan, Kim (John) Hagie and Kelley (Dave) Schroeder, as well as nieces, nephews, extended relatives and many dear friends.

Dennis was preceded in death by his parents, Bob and Cathy Sullivan.

For the people closest to him, the memories will extend far beyond a list of accomplishments. They will remember the sound of his laughter, the music he loved, afternoons spent watching sports, the gardens he carefully maintained and the sight of Papa proudly supporting another family event.

Dennis “Sully” Sullivan Funeral and Celebration of Life

Family and friends will gather to honor Dennis on Thursday, August 27, 2026, at Good Shepherd Catholic Church in Menomonee Falls.

Visitation is scheduled to begin at 2 p.m., followed by Mass at 4 p.m.

Following the service, loved ones are invited to gather at The Hot House Tavern in Menomonee Falls for food, drinks and a celebration of Dennis’ life.

It will offer those who knew Sully an opportunity to exchange stories and remember a man whose 72 years were filled with family, friendship, sports, music and hard work.

Dennis “Sully” G. Sullivan leaves behind a legacy visible most clearly in the family he loved so fiercely. From his days as a gifted young athlete to nearly four decades as a welder, years behind a drum kit and countless hours spent cheering for his children and grandchildren, Dennis lived a life filled with the people and passions that mattered to him.

His family will remember a devoted husband, father and Papa. Friends will remember the humor, personality and conversations. And those who shared his love of sports and music will remember a man who never lost his enthusiasm for the things that brought people together.

May Dennis “Sully” G. Sullivan rest in peace, and may Pauline, his children, grandchildren, siblings and everyone mourning his passing find comfort in the many memories they created with him.

Disclaimer

This obituary is based on information available at the time of publication. Details concerning Dennis “Sully” G. Sullivan’s death, battle with esophageal cancer, biography, surviving family and funeral arrangements should be confirmed through appropriate family or official funeral sources. Information may be updated if additional verified details become available. This article is intended for general informational and memorial purposes and should not be treated as a substitute for an official obituary or family announcement.