Helen Hayes Theatre, initially known as the Little Theatre, is a Broadway theatre located at 240 West 44th Street in Midtown Manhattan. With 597 seats, it is the smallest theatre on Broadway; it gave birth to what became known as the Little Theatre Movement in the early 20th century.

The Little Theatre was designed by the architect Harry Creighton Ingalls of the firm Ingalls & Hoffman, and built by Winthrop Ames; its name was chosen due to both the theatre's small size (with a seating capacity of only 300), and its goal to create intimate productions.
The theatre opened on March 12, 1912 with John Galsworthy's play The Pigeon. Other plays opening that year include.

In 1979, Martin Markinson and Donald Tick bought the theatre from Westinghouse for $800,000.
The theatre was named for Helen Hayes in 1983 when the actress' existing namesake theatre on West 46th Street was demolished (along with the Morosco Theatre and the Bijou Theatre), in order to construct the New York Marriott Marquis.
In July 2008 it was announced that Markinson and the Tick family planned to sell the theatre to the Second Stage Theatre company for an undisclosed price. Second Stage said it needs to raise $35 million to then possibly buy the theatre, which would likely be renamed.Second Stage's first season is targeted for 2013.
Rock of Ages achieved the box office record for the Helen Hayes Theatre. The production grossed $745,205 over nine performances, for the week ending December 31, 2012.