Walter Arthur Mueller—“Walt” to all who loved him—entered eternal rest on December 1, 2025, in St. Louis, Missouri, at the age of 84. Born in East St. Louis, Illinois, to Walter Arthur Mueller Sr. and Ada (Zeepaert) Mueller, both now deceased, Walt lived a rich and purposeful life grounded in faith, family, hard work, and service to others.
A proud 1959 graduate of Assumption High School, Walt won the 1958 American Legion Oratory Contest for the city of St. Louis and advanced to the state competition. His talent and academic excellence earned him multiple four-year college scholarships. He began his studies at Saint Louis University and later became largely self-taught in financial management—a testament to his lifelong curiosity and determination.
Walt’s distinguished career took him from the Treasurer’s Department at Union Electric to financial work on the F-4 Phantom program at McDonnell Douglas, and ultimately to senior executive leadership in the Missouri lead/zinc and Missouri/Minnesota iron-ore mining industries.
Service and faith were the heartbeat of his life. He mentored young boys as a devoted Webelos leader, served as Past President of Rotary International, and lived his Catholic faith deeply as a proud Knight of Columbus. An accomplished amateur photographer, he saw beauty in everyday moments, and his love of symphonic music brought light and harmony to his home. He was a prolific writer in his later years with creative and autobiographical writing.
Walt will be remembered for his intellect and generosity, his charming nature and ability to win over strangers, his service to community, and his unwavering love for his family.
He is survived by
- his beloved wife of 65 years, Carol (Brennan) Mueller, who he adored deeply;
- his children Michelle Danis (Rick), Dianne St. Clair, Robert Mueller (Angela), Mary Tiller (Jim), and Joseph Mueller (Jessica);
- his fourteen cherished grandchildren: Jessica Carter, Stephanie Long (Nick), Jon Johnson (Stacey), Jason Lashley (Lianna), Andrea Penisten, Sarabeth Penisten, Brittany Penisten, Michael Penisten, Rain Tiller, Phoenix Tiller (Sally), Faith Daria Mueller (Jack), Ally Mueller, Dominick Mueller, and Austin Mueller;
- his seventeen great-grandchildren: Caroline, Wesley, Dylan, and Zackary Carter; Maxwell Long-Penzer; Olivia Johnson, Tristan Testerman, Ava and Sophia Martin; Everly Lashley; Jack and Adalet Penisten; Isaiah and Gabriel Penisten, Autumn and Skylar Testerman; Emali Penisten; and one great-great-grandchild: Luna Menjivar-Testerman;
- his sister-in-law Cathlene (Brennan) Albrecht, and his brother, Richard H. Mueller.
Preceding him in death are his sister, Patricia (Mueller) Herschbach and their parents.
A special thank you to son-in-law Rick Danis for his constant support, devotion, and loving presence by Walt’s side.
Visitation will be held Monday, December 29, 2025, from 4:00–8:00 p.m. at Kutis South County Chapel, 5255 Lemay Ferry Road, St. Louis, MO 63129. A Funeral Mass will be celebrated Tuesday, December 30, 2025, at 10:00 a.m. at St. Catherine Laboure Catholic Church, 9740 Sappington Road, with private interment to follow at Resurrection Cemetery.
In lieu of flowers, memorial contributions may be made to Mosaic Health at supportmosaic.org.
Walt’s family finds comfort knowing he is now at peace and forever watching over the family he cherished so deeply.