William Jackson Keighley (August 4 1889, Philadelphia, Pennsylvania - June 24 1984, New York, New York) was an American stage actor and Hollywood film director.

After graduating from the Ludlum School of Dramatic Art, Keighley began acting at the age of 23. By the 1910s and 1920s, he was acting and directing on Broadway. With the advent of talking pictures, he relocated to Hollywood. He eventually signed with Warner Bros., where he proved adept at directing in a wide variety of genres. He was the initial director of The Adventures of Robin Hood, starring Errol Flynn, but was replaced by Michael Curtiz. During World War II, he supervised the U.S. Army Signal Corp's motion picture unit. He retired in 1953 and moved to Paris with his actress wife Genevieve Tobin.

William Keighley's professional career spanned three distinct mediums: the theatre, motion pictures and, finally, radio. Initially trained as a stage actor and Broadway director, he arrived in Hollywood shortly after the advent of sound, landing a job with Warner Brothers (where he spent most of his career) as an assistant director and dialog director before helming his first film there in 1932. Keighley's gangster films of the period, such as 'G' Men (1935) and Bullets or Ballots (1936), are models of the kind of fast-paced, tightly made, exciting films that Warner's specialized in--and which kept the cash flowing in during the studio's devastating losses of the period. Interestingly, although his career is closely associated with the meteoric ascent of James Cagney, the two men did not particularly care for each other, as Cagney was somewhat put off by what he felt were Keighley's phony European affectations (something the director acquired during his tenure on Broadway in the early 1920s and which would carry over into his later career in radio). However, much like the working relationship between Errol Flynn (I) and director Michael Curtiz (although far less volatile), both Cagney and Keighley did some of their best work together. Keighley also directed comedies, the best of which is Man Who Came to Dinner, The (1942). He was assigned by Warners to its prestigious Technicolor epic Adventures of Robin Hood, The (1938) with Flynn (although initially it was to be with a wildly miscast Cagney in the lead!), but following several weeks of shooting he was replaced by Curtiz (although receiving co-director credit) when studio executives thought that he was taking too long, they weren't satisfied with the film's pace and the costly epic--the most expensive picture in Warners history up to that time--was not going in the direction they thought it should. Keighley's film output declined in the late 1940s and early 1950s, roughly coinciding with his newfound interest as a radio host (his aristocratic voice was ideal for the medium) and his films met with less success, although he did turn out a crackerjack crime drama, Street with No Name, The (1948). He retired from directing after his last film, Master of Ballantrae, The (1953)--a beautifully shot but somewhat lumbering swashbuckler with an out-of-shape Errol Flynn--and he and his wife, actress Genevieve Tobin, moved to Paris, France, after he left CBS Radio in 1955.