David Martin Duff, 77 of Galena, IL passed away November 18, 2023, at UW Madison Hospital. A celebration of life will be held at a later date. The Furlong Funeral Chapel, Galena is assisting the family. David was born June 22, 1946, in Kansas City, MO the son of Kenneth and Katherine (Kriley) Duff. He served in the United States Navy from 1966 until his honorable discharge in 1970. David graduated from the University of Central Missouri with his undergraduate and master’s degrees. David was united in marriage to Marilyn Kay Ragan on February 4, 1972, in Warrensburg, MO. He was employed by JI Case Company as a product manager for 47 years until his retirement. David was an active member of the Kiwanis Club in Racine, WI, and Galena. He enjoyed restoring his 1926 Chevy, playing golf with his friends, and relaxing with his dogs Libby and Izzy. David is survived by his wife of fifty-one years, Marilyn Duff, a daughter, Constance (Michael) Bruzas, two grandchildren, Christopher Bruzas and Elizabeth Bruzas, and his sister, Mary Kay Lorenzo. He was preceded in death by his parents, and son, Robert Stephen Duff. In lieu of flowers, memorials may be given to the Kiwanis Club of Galena and the American Cancer Society in memory of David.