Age 96, of Upper St. Clair, formerly of Derry Township, passed away on April 15, 2026, surrounded by his loving family. Wilbur was a kind, caring man, who had a great sense of humor, and will be missed by all who knew him. Beloved husband of the late Margaret L. “Peggy” Stemmler, loving father of Peggy Stemmler, David (Judi) Stemmler, Karen (Mark) Krysevig and Kevin (Larry) Stemmler, devoted grandfather of Kaitlin (Gary) Debar, Kristin (fiancé Adam) Stemmler, and Michael (fiancé Christine) Stemmler, great grandfather of Dylan Debar, brother-in-law of Ralph Dornauer. He is preceded in death by his parents, Gust and Irene (Shrum) Stemmler, four siblings, Martha Belle (late Bob) McBroom, Loretta (late Jim) McBroom, Leroy Stemmler, and Evelyn “Jane” Dornauer. Also survived by many nieces and nephews. Wilbur was a 1947 graduate of Derry Township High School, where he was one of two seniors to letter in four varsity sports: football, baseball, track and basketball. He proudly enlisted and served in the U.S. Army during the Korean War, from 1951-1953. In Korea, he served as a corporal and company clerk of the 52nd Replacement Company. Wilbur was a 1955 graduate of St. Vincent College and worked in the Derry Area School District as a teacher and guidance counselor for 36 years. He earned his Master's of Education - School Counseling from Indiana University of Pennsylvania in 1961. He was well known for his love of gardening and growing vegetables to share with family and friends. He was a lifelong reader and enjoyed hunting and fishing in his younger years. Wilbur was an avid Pittsburgh sports fan and was looking forward to the Pirates winning their next World Series championship. He was a member of Resurrection Parish, American Legion Post 515, a life member of VFW Post 444, American Slovak Society, Kingston Vets and Sportsmen’s Club, and the Greek Club. He was also a member of the 1952 Oaklawn Oaks championship baseball team. The family would like to thank the staff of Friendship Village of South Hills - Assisted Living and 365 Hospice for the compassionate care that they provided Wilbur. All services and interment at the National Cemetery of the Alleghenies were private. Memorial contributions may be made to the Greater Pittsburgh Food Bank by mail at 1 N. Linden Street, Pittsburgh, PA 15110 or online at pittsburghfoodbank.org/tribute.