Air Vice Marshal Cresswell Montagu Clementi CB, CBE (30 December 1918 – 26 August 1981) was a senior Royal Air Force (RAF) commander.

He was born on 20 December 1918 in British Guiana during his father's posting there as Colonial Secretary (1913–1922).

He joined the Royal Air Force Volunteer Reserve in 1939, and was granted a permanent commission in the RAF in 1946.

He attended the British nuclear tests in 1958 at Christmas Island.

[3] Clementi married Susan Pelham (1918–2006) in 1940 and had three children: