In 1925, Foley visited the United States on a Rockefeller Travelling Fellowship for a year, returning in 1926 to a Fellowship at Gonville and Caius College, Cambridge, receiving here his Ph.D. in 1927. The same year, he was appointed Huddersfield Lecturer in Special Pathology at Cambridge. In 1931 he succeeded to the Joseph Hunter Chair of Pathology at the University of Sheffield and became assistant professor of pathology at the University of Sheffield. From 1935 to 1962 he was a professor at the Sir William Dunn school of pathology at Oxford.