Michael “Mike” Shayne is a fictional private detective created in the late 1930s by writer Brett Halliday, the best-known pseudonym of author Davis Dresser. Shayne made his literary debut in the 1939 novel Dividend on Death and quickly became one of the enduring private-eye characters of American mystery fiction.

Dresser wrote the first fifty Michael Shayne novels, with another twenty-seven later written by other authors under the Brett Halliday name, bringing the series to a total of 77 novels. The character also appeared in hundreds of short stories, motion pictures, radio programs, television and comic books, becoming a familiar figure to several generations of mystery fans.

The Shayne novels were known for their fast-moving plots, colorful characters and carefully constructed mysteries. A familiar element of many stories was Shayne gathering the suspects together and explaining the clues before revealing the identity of the murderer. Reporter Tim Rourke became one of the most important recurring characters and a frequent companion in Shayne's investigations.

In the early novels, Shayne was married to Phyllis Shayne. After the motion-picture rights to the character were sold, Dresser eventually removed Phyllis from the series. Her death marked a noticeable change in the books, with some of the lighter comedy of the earlier adventures giving way to a tougher and more serious tone.

Michael Shayne reached the motion-picture screen in 1940 with Lloyd Nolan in Michael Shayne, Private Detective. Nolan went on to portray Shayne in seven films produced by Twentieth Century Fox between 1940 and 1942. The character later returned to the screen in a series of five films starring Hugh Beaumont. Shayne was also heard in several radio adaptations during the 1940s and 1950s and returned to television in 1960–1961, when Richard Denning portrayed the detective in a 32-episode NBC series.