"The Adventures of Philip Marlowe" was a hardboiled detective radio series based on Raymond Chandler's iconic private eye. Unlike many other detective shows of the era, it was known for its serious tone, with fewer lighthearted moments.

The show premiered on NBC in June 1947 as a summer replacement for Bob Hope, titled "The New Adventures of Philip Marlowe," starring Van Heflin. The first episode adapted Chandler's short story "Red Wind," and the NBC run concluded in September 1947.

In 1948, the series moved to CBS and was renamed "The Adventures of Philip Marlowe," with Gerald Mohr taking on the lead role. This CBS version also began with a different adaptation of "Red Wind." By 1949, it had become the most popular radio program. The CBS series aired for 114 episodes, from September 1948 to September 1950.

From July to September 1951, the show briefly returned as a summer replacement for "Hopalong Cassidy," with Mohr reprising his role, except for one episode in 1950 featuring William Conrad.

A notable episode, "The Birds on the Wing" (November 26, 1949), famously broke the fourth wall at both the beginning and end. Marlowe mentions reading Chandler's latest novel, "The Little Sister," and in the conclusion, Gracie Allen asks Marlowe to find a radio show for her husband, George Burns.

Lyn Murray composed the program's music. The theme used in the first two NBC episodes, where Marlowe narrates the opening of Chandler's "Red Wind," later became a prominent motif in Murray's score for Alfred Hitchcock's "To Catch a Thief" (1954).

Despite its popularity, "The Adventures of Philip Marlowe" lacked consistent sponsorship, with only brief periods supported by Ford Motor Company and Wrigley's Gum in 1950.

Raymond Chandler had minimal involvement with the radio series, content with the weekly royalties for his character's use and expressing moderate satisfaction with Gerald Mohr's portrayal of Marlowe.

The first NBC episode's script was by Milton Geiger, which Chandler found "thoroughly flat." The CBS version, produced and directed by Norman Macdonnell, was better received. The writing team for the CBS series included Gene Levitt, Robert Mitchell, Mel Dinelli, and Kathleen Hite, with music by Richard Aurandt and Roy Rowan as the announcer. The cast alongside Gerald Mohr featured actors such as Jeff Corey, Howard McNear, Parley Baer, Lawrence Dobkin, Virginia Gregg, Gloria Blondell, and Lou Krugman.