Following proposals for religious and philanthropic work in London made to the Leysian Christian Union, the Leysian Mission was founded in 1886 and from then until the present former pupils of The Leys School have engaged in every aspect of its work. Its first premises were in Whitecross Street. The first resident lay worker was appointed in 1887, visiting the homes of the sick and poor and conducting a Mothers' Meeting with some 200 members. Activities included medical work, a working men's club, educational classes for boys, a large Sunday School and weeknight entertainments. The Mission moved to larger premises in Erroll Street in 1890, and again in 1904 to extensive premises (by J.J. Bradshaw) at the junction of Old Street and City Road.
A Commission appointed by the London Committee met in 1988 to consider the Mission's future and an amalgamation with Wesley's Chapel, City Road took place in 1989, bringing together two complementary traditions. Sale of the Leysian Mission premises enabled alterations to be made at Wesley's Chapel to accommodate the local and wider ministry. It also supports ministry among those experiencing deprivation in inner London and elsewhere, in keeping with the Mission's original purpose.