Studio 54 is a Broadway theater and former nightclub at 254 West 54th Street in Midtown Manhattan, New York City. Opened as the Gallo Opera House in 1927, it served as a CBS broadcast studio in the mid-20th century. Steve Rubell and Ian Schrager opened the Studio 54 nightclub, retaining much of the former theatrical and broadcasting fixtures, inside the venue in 1977. Roundabout Theatre Company renovated the space into a Broadway house in 1998.

The producer Fortune Gallo announced plans for an opera house in 1926, hiring Eugene De Rosa as the architect. The Gallo Opera House opened November 8, 1927, but soon went bankrupt and was renamed the New Yorker Theatre. The space also operated as the Casino de Paree nightclub, then the Palladium Music Hall, before the Federal Music Project staged productions at the theater for three years starting in 1937. CBS began using the venue as a soundstage in 1942, then as a television studio until 1975.

Schrager and Rubell opened the Studio 54 nightclub on April 26, 1977, as disco was gaining popularity in the U.S. Infamous for its celebrity guest lists, quixotic entry policies, extravagant events, rampant drug use, and sexual hedonism, Studio 54 closed in 1980 after Schrager and Rubell were convicted of tax evasion. A scaled-back version of the nightclub continued under new management before becoming the Ritz rock club in 1989, then the Cabaret Royale bar in 1994.