He was educated at Oundle School and at Trinity College, Cambridge, graduating with a bachelor's degree in mechanical sciences.

He was commissioned into 4th County of London Yeomanry (Sharpshooters), Territorial Army in 1939, and held technical appointments in connection with tank construction and testing (advising SEAC, 1940–43) and served in India and Burma, 1944–45.

[1] Erroll was elected as Member of Parliament for Altrincham and Sale in 1945, holding the seat until 1964.

In 1964 he was raised to the peerage as Baron Erroll of Hale, of Kilmun in the County of Argyll.

[3] In 1999, aged 85, he was awarded a life peerage as Baron Erroll of Kilmun, of Kilmun in Argyll and Bute,[4] to allow him to sit in the House of Lords following the passing of the House of Lords Act 1999, which excluded hereditary peers.