He was born in Newbury, Berkshire the son of John Langley, the local schoolmaster, and his wife, Mary Groom.

In 1871 he won a place at St John's College, Cambridge, where he graduated MA before continuing multiple postgraduate studies, gaining several doctorates.

[2] Langley is known as one of the fathers of the chemical receptor theory, and as the origin of the concept of "receptive substance".

A brass plaque to Langley's memory exists in Trinity College Chapel at Cambridge University.

[8] Langley married at St. Mary′s church, Montrose, on 10 September 1902 Vera Kathleen Forsythe-Grant (d.1932), third daughter of Frederick Grant Forsyth-Grant, of Ecclesgreig, Kincardineshire.