Hayward came to Broadway in 1935 with a production of Coward’s Point Valaine working with Alfred Lunt and Lynn Fontanne. The play, described as one of Coward’s worst and poorly received critically and popularly, only ran for a short time. The play ran six weeks and was considered a failure, but Hayward won the Donaldson award, a precursor to the Tonys and as a consequence signed a four-picture contract with MGM.

In 1938 Hayward starred in The Duke of West Point (1938) for producer Edward Small, who signed him to make three films over the next five years, meaning he was unable to reprise his part as the Saint.

Hayward married actress/director Ida Lupino on 17 November 1938 in a quiet civil ceremony held in the Santa Barbara courthouse. After he returned from the war, he was drastically different, which caused a strain in the marriage. They were divorced in 1945. He then met Peggy Morrow, and after dating for a while, they married on 29 May 1946. They divorced four years later on 13 March 1950.

During World War II, Hayward enlisted in the United States Marine Corps in July 1942. He commanded a photographic unit that filmed the Battle of Tarawa in the documentary With the Marines at Tarawa—winner of the 1944 Academy Award for Best Documentary (Short Subject). Hayward was awarded the Bronze Star Medal.

Returning to Hollywood, he played Philip Lombard in the 1945 film version of And Then There Were None (1945) for René Clair.

Hayward was cast as the first screen incarnation of Simon Templar in Leslie Charteris’ The Saint in New York (1938) at RKO. The film was a hit and would eventually lead to a long-running series. However, the next five films in the series starred George Sanders as Templar. Hayward would eventually reprise the role in The Saint’s Return in 1953.

Hayward starred in the 1954 syndicated television series The Lone Wolf, which ran for 39 episodes. He did episodes of Matinee Theatre (“Beginning Now”), Climax! (“A Promise to Murder”), TV Reader’s Digest (“The Voyage of Captain Tom Jones, Pirate”), Lux Video Theatre (“So Evil My Love”, “Suspicion”), The O Henry Playhouse (“Hearts and Hands”), Studio One in Hollywood (“Balance of Terror”), Schlitz Playhouse (“A Contest of Ladies”), The Highwayman, and Decision (“Stand and Deliver”).

For his contributions to the motion picture and television industries, Hayward was honored in 1960 with two stars on the Hollywood Walk of Fame at 1500 and 1680 Vine Street, respectively.

Hayward starred in the 1961 British television series The Pursuers (1961–62). Hayward’s other television work includes the Alfred Hitchcock Hour (“Day of Reckoning”), Kraft Television Theatre (“Dead on Nine”), Rawhide, and Burke’s Law.

Louis Hayward died on 21 February 1985 at the age of 75 in Palm Springs, California from lung cancer.