Sir Ralph Ellis "Robin" Brook (19 June 1908 – 25 October 1998) was a British merchant banker and a director of the Bank of England.
He was knighted in the 1974 New Year Honours.
His wife Helen Brook was founder of the Brook Advisory Centres.As a fencer, he competed at the 1936 and 1948 Summer Olympics.The son of a surgeon, Brook was educated, through scholarships, at Eton College and subsequently at King's College, Cambridge, where he studied under Maynard Keynes, earning a double first in Economics.