Stephen Gaghan (born May 6, 1965) is an American screenwriter and director. He is noted for writing the screenplay for Steven Soderbergh's film Traffic, based on a Channel 4 series, for which he won the Academy Award, as well as Syriana which he wrote and directed.
Gaghan was born in Louisville, Kentucky, the son of the former Elizabeth Jane Whorton and her first husband, Stephen Gaghan (d. 1980), and a stepson of Tom Haag. Gaghan attended Kentucky Country Day School, a college preparatory school in Louisville. He was an All-State soccer player where he held the assist record at the school for nearly three decades. He is a grandson of Jerry Gaghan, a newspaper columnist and drama critic for Variety and the Philadelphia Daily News. Gaghan wrote in a 2001 article in Newsweek, "I also wanted to be a writer, like my grandfather, who carried a card in his wallet that read, "If you find me, call my son at this number..."