John “Jack” E. Mullin, 75, of Delavan, passed away on Wednesday, March 4, 2026 at Aurora Zilber Family Hospice in Wauwatosa.
Jack was born on June 3, 1950 to Edmund and Eileen (Brett) Mullin and grew up in Oak Park, Illinois. He was as a sheet metal worker for 42 years for Local 73 in Chicago. He was united in marriage to Lynn Freeman in 2008 in Grayslake, Illinois. Jack loved golfing, traveling, and classic Rock and Roll. He even had Cheap Trick play in his backyard. Jack was known by many for his amazing memory.
Jack is survived by his wife, Lynn; and two stepchildren, Sarah (Jeff) Coleman, of Arlington Heights, Illinois, and Ryan Dontsow, of Denver. He was known as Grampa Jack to Abigail, Gavin, Greyson, and Austin; had three sisters, Margaret (Stef) Lopata, Marybeth Mullin, and Mary Eileen Mullin; two brothers, Robert (Patty) Mullin, and Patrick Mullin; and was uncle to Caitlin, Colleen, Christopher, Tim, Peter, and Ryan.
Jack is preceded in death by his parents.
Celebration of Life will be held at a later date to be announced. Monroe Funeral Home in Delavan is assisting the family.