The Lyceum Theatre is a Broadway theater at 149 West 45th Street, between Seventh Avenue and Sixth Avenue, in the Theater District of Midtown Manhattan in New York City. Opened in 1903, the Lyceum Theatre is one of the oldest surviving Broadway venues, as well as the oldest continuously operating legitimate theater in New York City. The theater was designed by Herts & Tallant in the Beaux-Arts style and was built for impresario Daniel Frohman. It has 922 seats across three levels and is operated by The Shubert Organization. The facade became a New York City designated landmark in 1974, and the lobby and auditorium interiors were similarly designated in 1987.

The theater maintains most of its original Beaux-Arts design. Its 45th Street facade has an undulating glass-and-metal marquee shielding the entrances, as well as a colonnade with three arched windows. The lobby has a groin-vaulted ceiling, murals above the entrances, and staircases to the auditorium's balcony levels. The auditorium has an ornately decorated proscenium and boxes, but the ceiling and walls are relatively plain. An apartment above the lobby, originally used by Frohman, was converted to the headquarters of the Shubert Archives in 1986. The stage door entrance is through 152 West 46th Street, a 10-story wing designed by Herts & Tallant, which also houses the dressing rooms and some backstage facilities.

The current Lyceum replaced Frohman's earlier Lyceum on Fourth Avenue, which closed in 1902. The current theater opened on November 2, 1903, with the play The Proud Prince. Frohman's brother Charles served as the theater's manager until dying in 1915, and Daniel Frohman subsequently partnered with David Belasco to show productions at the theater until 1930. Afterward, Frohman lost the theater to foreclosure in the Great Depression, and a syndicate composed of George S. Kaufman, Max Gordon, and Moss Hart bought the theater in 1940. The Shubert Organization has operated the theater since 1950. The Lyceum was leased to the Association of Producing Artists (APA) and Phoenix Theatre in the late 1960s and to the National Actors Theatre during much of the 1990s.