John Robert "Jack" Nicholson, PC OBE QC (December 1, 1901 – October 8, 1983) was a Canadian lawyer, businessman, politician and the 21st Lieutenant Governor of British Columbia.
Born in Newcastle, New Brunswick (now Miramichi), he graduated from the Dalhousie University law school in Halifax.
In 1924, he moved to Vancouver, British Columbia and practised law.
During World War II, he was a deputy controller in the Department of Munitions and Supplies.
In 1962, Nicholson was elected to the Canadian House of Commons for the riding of Vancouver Centre and was re-elected in 1963 and 1965.