Harley Granville-Barker (25 November 1877 – 31 August 1946) was an English actor, director, playwright, manager, critic, and theorist.

After early success as an actor in the plays of George Bernard Shaw, he increasingly turned to directing and was a major figure in British theatre in the Edwardian and inter-war periods.

As a writer his plays, which tackled difficult and controversial subject matter, met with a mixed reception during his lifetime but have continued to receive attention.

This landed him many roles such as; Tanner in Man and Superman, Cusins in Major Barbara, Marchbanks in Candida, and Dubedat in The Doctor's Dilemma.

In 1904 he collaborated with William Archer to write a book that argued for a national theatre; unfortunately, it was a lost cause that became one of the biggest disappointments in his life.

The year before he met his first wife, Granville-Barker wrote The Voysey Inheritance which is considered to be a masterpiece of the Edwardian stage.

In 1909, three volumes of his plays, The Voysey Inheritance, Waste, and The Marrying of Ann Leete, were published in a limited edition of 50 copies printed on handmade paper in a slipcase.

He divorced McCarthy and married an American writer named Helen Huntington who supposedly disliked the stage, actors, and especially Shaw.

Recently, the negative characterization of Helen "as a theatre-hating woman who ruined Barker's career" has been disputed, and her dislike of the theater refuted, on the basis of Granville-Barker's early correspondence with her.

"[2] He later settled in Paris where he collaborated with Huntington on translating the comedies of Martínez Sierra and the Álvarez Quintero brothers.