The 2009 season was the Kansas City Chiefs' 40th in the National Football League (NFL), their 50th overall, and their first under head coach Todd Haley and general manager Scott Pioli. The Chiefs attempted to improve on their 2–14 record from 2008 with the third overall selection in the 2009 NFL Draft. In 2009, the Chiefs also honored the induction of Derrick Thomas, the team's former linebacker from 1989 to 1999, into the Pro Football Hall of Fame. Thomas' jersey number 58 was officially retired by the franchise after having been unissued since Thomas' death in 2000.

Richard Todd Haley is an American football coach who most recently was head coach for the Memphis Showboats of the United States Football League (USFL).