Charles Ryle Fay (13 January 1884 – 19 November 1961) was a noted British economic historian. He was a strong advocate of co-operation, workers' rights and women's rights.
He was educated at Merchant Taylors' Boys' School, Crosby and King's College, Cambridge, where he was a student alongside John Maynard Keynes. The two remained friends until Keynes' death. One of his students, Austin Robinson, described him as an "exuberant, argumentative, devoted pupil of Marshall, but almost wholly innocent of any understanding of economic theory."
Fay's papers are held at the Public Record Office of Northern Ireland.