During the 1920s, whilst the theatre in Birmingham was experiencing some difficulties, Sir Barry ventured into producing in London. Drinkwater's Abraham Lincoln had already been well-received at the Lyric Theatre in Hammersmith in February 1919 and went on to tour the U.S.A. In 1922, the Regent was the venue for Rutland Boughton's opera, The Immortal Hour. This would go on to be revived in successive years and established Gwen Ffrangcon-Davies as a favourite with the audience. This was reinforced by her performance in Romeo and Juliet also starring John Gielgud, directed by H.K Ayliff. From 1924, Sir Barry leased the Royal Court, where Back to Methuselah(1923)and The Farmer's Wife (1924) by Eden Philpotts were staged, making Cedric Hardwicke a star.
The success of these productions encouraged Sir Barry to use the Kingsway Theatre for experimental productions, such as, Hamlet in modern dress (1925) and Rosmersholm (1926). Whilst these productions generated much attention they were not financial successes, and by 1932 when Sir Barry stopped producing in London, from over forty different productions only five had made a profit;The Farmer's Wife, The Barretts of Wimpole Street, Yellow Sands, The Apple Cart and Evensong. However, despite the financial loss, the innovative and experimental productions from that period remain influential to this day.