Sir Harold Bernard St. John, KA (16 August 1931 – 29 February 2004) was a Barbadian politician who served as the third prime minister of Barbados from 1985 to 1986.

He was professionally trained as a lawyer at the University College London and was called to the Bar at the Inner Temple in 1958.

The following year he was defeated in the elections by Errol Barrow and the Democratic Labour Party.

In 1994 when the BLP regained power, he did not return to the Cabinet and served instead as a backbencher under Owen Arthur.

He left his widow Lady Stella (née Hope) and three children: Bryte, Charmaine and Nicole.