Commander Sir Peter Garnett Agnew, 1st Baronet (9 July 1900 – 26 August 1990) was an officer in the Royal Navy and a Conservative Party politician.

After a term as Aide-de-camp to the Governor of Jamaica, he was assigned to the battleship Queen Elizabeth in August 1928, transferring to the Royal Yacht Victoria and Albert in May 1930.

[3] He served as Parliamentary Private Secretary to Walter Runciman, the President of the Board of Trade, in 1935–37, and to Sir Philip Sassoon, First Commissioner of Works, in 1937–39.

He was in command of the destroyer Ramsey from November 1940 to March 1941, receiving a Mention in Despatches on 1 January 1941.

After his death in 1990 at the age of 90, he was succeeded in the baronetcy by his son, Sir Quentin Agnew-Somerville, 2nd Baronet, father of the actress Geraldine Somerville.