Sir Ian Maurice Gray Prosser (born 5 July 1943) is a British businessman.
Prosser was born in Bath, England and educated at King Edward's School, Bath, Watford Grammar School for Boys and Birmingham University.
He is Chairman of The Navy Army & Airforce Institutes, Chairman BP Pension Trustees PLC and a non-executive director of Sara Lee Corporation based in Chicago. He was Chairman & CEO of Bass PLC and latterly Chairman of InterContinental Hotels until his retirmement in 2003. He is a former non-executive Deputy Chairman of BP Plc, having joined as a non-executive Director in 1997 and retired on 15 April 2010. He was formerly senior independent director of GlaxoSmithkline, a non-executive director of The Boots Company and of Lloyds TSB.
Prosser received his knighthood in the 1995 New Year Honours List.