Harper (released in the UK as The Moving Target) is a 1966 American mystery film based on Ross Macdonald's 1949 novel The Moving Target and adapted for the screen by novelist William Goldman, who admired MacDonald's writings. The film stars Paul Newman as Lew Harper (Lew Archer in the novel), and was directed by Jack Smight, with a cast that includes Robert Wagner, Julie Harris, Janet Leigh, Shelley Winters, Lauren Bacall, and Arthur Hill.

The film pays homage to Humphrey Bogart's portrayals of Sam Spade and Philip Marlowe by featuring Lauren Bacall, Bogart's widow, who plays a wounded wife searching for her missing husband, a role similar to General Sternwood in the 1946 Bogart-and-Bacall film The Big Sleep.

Goldman received a 1967 Edgar Award for Best Motion Picture Screenplay. In 1975, Newman reprised his role in The Drowning Pool.