Graham John Yost (born September 5, 1959) is a Canadian film and television screenwriter. His best-known works are the films Speed, Broken Arrow, and Hard Rain and the TV series Justified.

In 2002, he created the widely acclaimed, yet short-lived drama series Boomtown. He has also written for the television series Herman's Head and Band of Brothers. He also created the short-lived NBC drama Raines.