Laurence van Cott Niven (/ˈnɪvən/; born April 30, 1938) is an American science fiction writer. His 1970 novel Ringworld won the Hugo, Locus, Ditmar, and Nebula awards. With Jerry Pournelle he wrote The Mote in God's Eye (1974) and Lucifer's Hammer (1977). The Science Fiction and Fantasy Writers of America gave him the 2015 Damon Knight Memorial Grand Master Award.
His work is primarily hard science fiction, using big science concepts and theoretical physics. It also often includes elements of detective fiction and adventure stories. His fantasy includes the series The Magic Goes Away, works of rational fantasy dealing with magic as a non-renewable resource.