Robert John Rolston Harcourt was a Unionist politician and coal merchant who served as Lord Mayor of Belfast during 1955 and 1956.

Harcourt first entered the Belfast Corporation in 1927 when he was elected as councillor for Court ward. He was appointed as High Sheriff of Belfast in 1949 and elected as an alderman in 1955.

Harcourt was a director of F. E. Harcourt & Co, coal merchants, which had its head office on High Street. He was a Fellow of the Institute of Directors.

In 1949, Harcourt won a by-election for the Woodvale seat in the Northern Ireland parliament. He represented the Ulster Unionist Party and served for five years. Harcourt resigned his parliamentary seat in 1950 when he accepted the role of Lord Mayor, which brought with it an ex officio position in the Senate (Upper House of NI Parliament). He was knighted in 1959.