The theatre opened on December 27, 1906 as the Hicks Theatre in honour of actor, manager and playwright Seymour Hicks, for whom it was built. Designed by W.G.R. Sprague in Louis XVI style, the theatre originally had 970 seats, but over the years boxes and other seats have been removed. The theatre is a pair with the Queen's Theatre, which opened in 1907 on the adjacent street corner.
The first play at the theatre was a musical called The Beauty of Bath by Hicks and Cosmo Hamilton. My Darling, another Hicks musical, followed in 1907, followed by the successful London production of the Straus operetta, A Waltz Dream in 1908. An astonishing event occurred midway through the run of the theatre's next major work, The Dashing Little Duke (1909), which was produced by Hicks. Hicks' wife, Ellaline Terriss, played the title role (a woman playing a man). When she missed several performances due to illness, Hicks stepped into the role — possibly the only case in the history of musical theatre where a husband succeeded to his wife's role.
In 1909, the house was renamed the Globe Theatre. Another "Globe Theatre", located on Newcastle Street, had been demolished in 1902 to make way for the Aldwych, and so the name became available. A number of notable productions ran at this Shaftesbury Avenue theatre and are listed below. Call It A Day by Dodie Smith opened in 1935 and ran for 509 performances, which was considered very successful for the slow inter-war years.
Terence Frisby's There's a Girl in My Soup, opening in 1966, ran for 1,064 performances at the theatre, a record that was not surpassed until Andrew Lloyd Webber's production of the Olivier Award-winning comedy Daisy Pulls It Off by Densie Deegan opened in April 1983 to run for 1,180 performances, the theatre's longest run. In 1987 Peter Shaffer's play Lettice and Lovage was a hit with Maggie Smith and Margaret Tyzack, running for 2 years. The theatre has presented several Alan Ayckbourn premieres, including 1990's Man of the Moment. More recently, Oscar Wilde's classic comedy, An Ideal Husband (1992) and One Flew Over the Cuckoo's Nest (2004) saw notable revivals. Refurbished in 1987, with extensive work on the gold leaf in the auditorium, the theatre is particularly notable for its beautiful circular Regency staircase, oval gallery and tower.
In 1994, in anticipation of the 1997 opening of a reconstruction of Shakespeare's Globe Theatre on the South Bank by Sam Wanamaker, the theatre was renamed in honour of British actor John Gielgud. In 2003, Sir Cameron Mackintosh announced plans to refurbish the Gielgud, including a joint entrance foyer, with the adjacent Queen's Theatre, facing on to Shaftesbury Avenue. Mackintosh's Delfont Mackintosh Theatres took over operational control of the Gielgud from Andrew Lloyd Webber's Really Useful Theatres in 2006. The Delfont Mackintosh group also consists of the Noel Coward Theatre, Novello Theatre, Prince Edward Theatre, Prince of Wales Theatre, Queen's Theatre, and Wyndham's Theatre.
Work on the facade of the theatre started in March 2007.