Reginald John Marsden Parker (February 7, 1881 – March 23, 1948) was the eighth lieutenant governor of Saskatchewan from 1945 until his death in 1948.

He got involved with local politics and was elected councilor in the rural municipality of Cote in 1904.

Parker was appointed to the provincial cabinet of James Garfield Gardiner as Minister of Municipal Affairs.

He served in the portfolio for ten years until the Saskatchewan CCF took power in the 1944 provincial election.

Parker was appointed lieutenant governor of the province by federal Prime Minister William Lyon Mackenzie King and was sworn in on June 25, 1945.