From Wikipedia, the free encyclopedia. Greydon Clark (born February 7, 1943) is an American film director, writer, producer, and actor, whose career spans several decades and genres, although the majority of his work has been low-budget action/horror productions. His most recent work was writing and directing the 1998 science fiction movie Stargames, featuring Tony Curtis. Description above from the Wikipedia article Greydon Clark, licensed under CC-BY-SA,full list of contributors on Wikipedia.