Michael T. "Mike" Gierczak, 79, Green Bay, passed away Sunday, July 6, 2025. He was born July 15, 1945, in Green Bay to Thomas and Geraldine (Dessart) Gierczak.

Mike graduated from East High School, Class of 1963. He met Karen Kienert in January of 1970 and the two married on October 10, 1970 at Immanuel Lutheran Church in Waupaca. Mike was a devoted member of First Evangelical Lutheran Church. Following Karen's retirement, they traveled together and especially loved their Transatlantic Cruises. Mike enjoyed sheepshead, hunting, fishing, cribbage, shooting pool, and spending time at the lake.

He is survived by his wife, Karen; children, Matthew (Tiffany) Gierczak, Amy Sachs, David (Heidi) Gierczak; grandchildren, Devan (Emilia), Michael (Nicole), Aaron, Jordan, Lydia, Elise; great-grandchildren, Miles, James; siblings, Steven (Jan) Gierczak, Ronald Gierczak, Joseph Gierczak, Patricia (Tom) Wertel; siblings-in-law, Marilyn Gierczak, Kathleen (Jim) Corrigan, Sandra (Richard) Lashua, Cynthia (John) Smith, Jacqueline (Eric) Spindt, Tim (Yvette) Kienert; nieces, nephews, other relatives, and friends.

Mike was preceded in death by his parents, Thomas and Geraldine; son-in-law, Brad Sachs; siblings; Richard Gierczak, Timothy Gierczak; in-laws, LaVerne and Avis Kienert; siblings-in-law, Diane Gierczak, Ted Andrews.

Friends and family will gather at First Evangelical Lutheran Church, 743 S Monroe Ave., from 1 PM to 3 PM on Saturday, July 12; Funeral Service to follow at 3 PM. Burial will be in St. John the Baptist Cemetery. To send online condolences, please go to www.BlaneyFuneralHome.com.

The family wishes to extend a special thank you to the staff at Cardinal Ridge for their exceptional care given to Mike.