Vice Admiral Sir (George Francis) Allan Trewby KCB (8 July 1917 – 23 July 2001) was a Royal Navy officer who ended his career as Chief of Fleet Support.

Born the eldest son of Vice Admiral George Trewby[1] and educated at the Royal Naval College, Dartmouth, Trewby joined the Royal Navy as a cadet in 1931 and chose to specialize in engineering.

[1] In 1954 was the winner of the Akroyd Stuart Award from the Institute of Marine Engineering.

[1] He was appointed Commander of the training establishment HMS Sultan in 1963 and Captain of HM Naval Base Portland in 1966.

[2] Promoted Rear Admiral in 1968, he became Assistant Controller for the Polaris Programme at the Ministry of Defence in 1968, and following promotion to vice admiral, was made Chief of Fleet Support in 1971; he retired in 1974.