Harry Max Harrison (born Henry Maxwell Dempsey; March 12, 1925 – August 15, 2012) was an American science fiction author, best known for his character the Stainless Steel Rat and for his novel Make Room! Make Room! (1966). The latter was the rough basis for the motion picture Soylent Green (1973). Harrison was (with Brian Aldiss) the co-president of the Birmingham Science Fiction Group.

Aldiss called him “a constant peer and great family friend.” His friend Michael Carroll said, “Imagine Pirates of the Caribbean or Raiders of the Lost Ark, and picture them as science-fiction novels. They’re rip-roaring adventures, but they’re stories with a lot of heart.”

The Science Fiction Hall of Fame inducted Harrison in 2004 and the Science Fiction and Fantasy Writers of America named him its 26th SFWA Grand Master in 2008 (presentation of the Damon Knight Award following in 2009). He became a cult hero in Russia.