William Koloseike '76, Emeritus

William “Bill” August Koloseike, 67, of Naperville, Illinois, passed away on November 6, 2025, surrounded by the family who meant everything to him.

 

Born on September 15, 1958, in Chicago, Illinois, Bill grew up with an adventurous spirit and a drive that carried him through every chapter of his life. After moving to Naperville, he built a life filled with love, laughter, and purpose alongside his wife of 41 years, Jan, their two children, Billy and Blake, and his two granddaughters, Kennedy and Remington — the people he was proudest of.

 

A true entrepreneur at heart, Bill owned and operated a successful chain of car dealerships across the Chicagoland area. His work was more than a career — it was a community. Bill treated everyone with respect and sincerity, building lasting friendships with employees, customers, and business partners alike.

 

Bill’s energy was boundless, and his zest for life was contagious. He was an avid triathlete, runner, and mountain biker, always seeking out a new challenge or trail to conquer. He found peace and joy on the water while boating in New Buffalo, Michigan, and pure exhilaration carving down the slopes on skis. Music was a constant companion in his life, and few things brought him more delight than the rumble of a classic Corvette engine and a favorite song playing on the radio.

 

Above all, Bill will be remembered for his generous heart, sharp wit, and the way he made those around him feel valued and loved. He had a gift for turning ordinary moments into lasting memories, and his presence filled every room with warmth and laughter.

 

Bill is survived by his loving wife, Jan; his children, Billy Koloseike and Blake (Max) Michaels; his granddaughters, Kennedy and Remington; his brother, Mark (Jean) Koloseike; and his sisters, Nina Koloseike and Judy (John) Spellman; and several nieces and nephews. He will be deeply missed by his family, friends, and all who had the privilege of knowing him.

 

A celebration of Bill’s life will be held in Naperville. Visitation will be held on Thursday, November 13th, 2025, from 2:00 P.M. to 8:00 P.M. at Beidelman-Kunsch Funeral Homes and Crematory located at 516 S. Washington Street, Naperville, Illinois 60540. Funeral service will be held on Friday, November 14th, 2025, at 10:30 A.M. at St. Raphael Catholic Church located at 1215 Modaff Road, Naperville, Illinois 60540. Entombment Assumption Catholic Cemetery in Wheaton, IL.