Sir Cyril Fred Fox FSA FBA MRIA (16 December 1882[1] – 15 January 1967) was an English archaeologist and museum director.

[2] With Iorwerth Peate, he established the Welsh Folk Museum at St Fagans, and with Lord Raglan, he authored a definitive history of vernacular architecture, Monmouthshire Houses.

Spotted by Professor H. M. Chadwick, he was soon allowed to proceed straight to doctoral study, and in 1922 he completed a Ph.D thesis entitled Archaeology of the Cambridge Region.

They include The Personality of Britain (1932), drawing attention to the differences between upland and lowland Britain; Offa's Dyke (1955), a seminal study of that great earthwork, and studies on Celtic Art, on the major discovery of early ironwork at Llyn Cerrig Bach in Anglesey; and Monmouthshire Houses, co-authored with Lord Raglan.

Together with his colleague Nash-Williams at the Museum of Wales, he collaborated with the artist Alan Sorrell on reconstruction drawings of the Roman excavations at Caerwent which were published in the Illustrated London News 1937–1942.