Michael Anthony O'Sullivan

Mike was born in Midland, Michigan where he spent most of his early years. He graduated from Midland High School and received an associate degree from Delta College. He went on to become a senior construction technical representative. Throughout his 35-year career, he was highly regarded amongst his coworkers and made many lasting friendships along the way.

Mike was a devoted family man and regarded his family above all else. He gifted them with time, love, and support unconditionally. Although his career required long hours, his family remained his top priority. He had endless talent, envious patience, and never met a problem he could not solve. He was a generous and kind man, extremely bright, and he had a great sense of humor. He went out of his way to help others whether or not they asked for it. Mike loved to cook and rarely needed a recipe to follow, as he had a natural talent for making amazing food. He was a tinkerer through and through. Organizing and reorganizing the garage, washing and waxing family vehicles, and finding things to fix were some of his hobbies. Mike was known among friends for his well-designed home renovations. Snowmobiling and hunting with his friends were yearly adventures for Mike. He also enjoyed camping and having cool refreshments. In recent years, dear friends Dani and Randy Wilcox gifted Mike’s family with visits to the U.P. where Mike enjoyed boating, campfires, and taking long naps by the lake. Mike loved being celebrated by his dearest friends and family at his birthday party earlier this summer.

Mike was welcomed to Heaven by his parents Sharon Chase and Jerry O’Sullivan; Grandma Anita and Grandpa Burt Chase; Aunt Laura Chase; Grandma Betty and Grandpa Bob O'Sullivan; Uncle Dick (Patti) O’Sullivan, Uncle Dave O’Sullivan, Uncle Tim O’Sullivan; cousin, John Paul O’Sullivan; brother-in-law, Jeff Birtles; and his beloved dogs Rocky, Buddy, and Rudy.

Mike is survived by beloved wife, Anne O’Sullivan; three children Adam DeLeon, Chanda DeLeon, Tre DeLeon; favorite granddaughter, Lianna DeLeon; sister, Christen O’Sullivan (Erick Gonzales); mother-in-law, Hope Golembiewski; favorite nephew, Malakai Gonzales; brother-in-law, “Little Buddy” Greg (Mary) Golembiewski; sisters-in-law Chris Hansen, Lisa Birtles, and Amy (Bob) Gehl; Aunt Becky (Joe) Etheridge; Aunt Carol (Jerry) Leigeb; Uncle Rocky Chase; Aunt Maureen (Jim) Maroney; Aunt Sue (Mike) O’Sullivan; Aunt Debra O’Sullivan; Mike’s bonus family Bob Sr. and Judy Heffner, Bob and Melanie Heffner, Grace Heffner, Jackson Heffner; and many loving nieces, nephews, cousins, and friends.

As one of his final wishes, Mike requested casual wear at his service; he wanted everyone to celebrate comfortably.

Visitation with the family will be held from 4-7 p.m. Thursday, September 11, 2025 at Cook Funeral Home (Byron Center Chapel), 2067 84th St. SW, Byron Center, MI 49315. A memorial service celebrating Michael's life will be held 11 a.m. Friday, September 12, 2025 at Cook Funeral Home (Byron Center Chapel), with visitation from 10-10:45 a.m. prior to the service.

In lieu of flowers, the family requests donations to be made in Mike’s memory to the Kent County Animal Shelter: https://checkout.shelterluv.com/donate/KCAS and/or

Feeding America West Michigan: https://www.feedwm.org/

The family welcomes memories and messages at www.cookcaresbyron.com in their guestbook online.