Donald John DeFore was an American actor. He is best known for his roles in the sitcom The Adventures of Ozzie and Harriet from 1952 to 1957 and the sitcom Hazel from 1961 to 1965, the former of which earned him a Primetime Emmy Award nomination.

The Adventures of Ozzie and Harriet is an American television sitcom that aired on ABC from October 3, 1952, to April 23, 1966, and starred the real-life Nelson family. After a long run on radio, the show was brought to television, where it continued its success, initially running simultaneously on radio and TV. In terms of seasons, it was the longest running live-action sitcom in U.S. television history until It's Always Sunny in Philadelphia surpassed it on December 1, 2021. The series starred the entertainment duo of Ozzie Nelson and his wife, singer Harriet Nelson, and their sons, David and Ricky. Don DeFore had a recurring role as the Nelsons' neighbor "Thorny".