Peter II (c. October 1946 – 21 June 1947) was a cat who was employed as the chief mouser to the Cabinet Office from 1946 to 1947, during the premiership of Clement Attlee.

Peter served just six months; in the early hours of 21 June 1947 he was struck by a car near the Cenotaph in Whitehall, and died shortly afterwards.

[1] His appointment occurred one month after Peter was euthanised on 14 November 1946 at the age of 17 owing to his no longer being an "efficient cat" and having "outlived his usefulness".

[2][3] The young kitten served a truncated term; in the early hours of 21 June 1947, around six months after his appointment,[2] Peter was struck by a car driven by a "Mr. R. B. Bisgood" in Whitehall while walking from the Home Office to the Cenotaph,[4] receiving "injury to the head, right shoulder and a lacerated jaw".

[5][6] After the collision, a police constable brought Peter to the door of the Home Office building at 3:15 am, and the Royal Society for the Prevention of Cruelty to Animals (RSPCA) was phoned five minutes later; their representative arrived on the scene at 3:35 am.