Donald Alan Dillingham, 80, of Overland Park, Kansas, passed away at home surrounded by his family on May 3, 2025. 

Born to Donald and Harriet Dillingham on July 10, 1944 in Wamego, Kansas, Alan was raised first in Manhattan and then in Herington, Kansas. He received a bachelor’s degree in physical science from Emporia State University where he met the love of his life, Mary Kay Pyle. They were married on October 14, 1967. Shortly thereafter, he proudly served a tour of duty in Vietnam as a United States Marine. He worked for several decades as a chemist and spent the latter part of his career in pharmaceutical clinical trials. In his spare time, Alan was an impressive athlete. He completed seven marathons and two triathlons, and he looked forward to biking across the state of Kansas every summer. He was an avid fan of KU basketball, the Tour de France, science fiction, gardening, rock and roll, his dachshunds, and most of all, his family. 

Alan was known and loved for his bottomless kindness to everyone. Empathy and decency came as naturally to him as breathing. He appreciated the small and simple pleasures of living, and he faced life’s difficulties with a ready smile and an excellent sense of humor. A class act to the end, he gave his all to every role he filled in this world; he was a good son, a caring brother, a loyal friend, a loving husband, a fantastic father, and the best grandfather. 

He is survived by his wife, Mary Kay; his daughters Katy Hutchins (Eric), Susan Dillingham, and Megan Bannen (Michael); his three grandchildren, Jack Hutchins, Hank Bannen, and Gus Bannen; his sister Janice Eberle and his brother Rick Dillingham. 

A visitation will be held at Porter Funeral Home in Lenexa, Kansas on May 8, 2025 from 10:00AM to 11:00AM, followed by a memorial service. It was Alan’s wish that any memorial tributes be made in the form of charitable donations to the Wounded Warrior Project. To donate online click here: https://www.woundedwarriorproject.org/