J. G. Jeffreys (born 1893), Australian schoolteacher who moved to England and founded Bryanston School in Dorset
George Jeffreys | Garland Jeffreys | Stephen Jeffreys | Sheila Jeffreys | Harold Jeffreys | Joyce Jeffreys | John R.F. Jeffreys | John Gwyn Jeffreys | J. G. Jeffreys | Jeffreys Bay | Gina Jeffreys | George Jeffreys, 1st Baron Jeffreys | Garland Jeffreys and Grinder's Switch | Alec Jeffreys |
John R.F. Jeffreys (1918–1941), British mathematician and World War II codebreaker