Glyn Keith Murray Mason CBE, DSO (29 May 1887 – 31 December 1972) was a British businessman, magistrate and Conservative politician.
Mason was born in 1887 to Edith Mason née Affleck and William Mason (1862–1947). His father, created a baronet in 1918 and 1st Baron Blackford in 1935, was a barrister, a magistrate and Lord of the Manor.
Mason served as a Colonel in the 14th Hussars, seeing action in World War I in France, Salonica and Palestine. He was awarded the Distinguished Service Order in 1916.
At the general election in November 1922, Sir Glyn was elected unopposed as Conservative Member of Parliament (MP) for Croydon North, then in Surrey. He kept his seat in the 1923, 1924, 1929, 1931 and 1935 general elections, facing Gilbert Foan for the Labour Party on three occasions. On 1 June 1940, Mason resigned his seat by accepting the stewardship of the Manor of Northstead.
During World War II, Mason served in the City of London Home Guard. He became a Justice of the Peace in 1946 in Somerset and succeeded his father as second Baron Blackford in 1947. He was a Lieutenant of the City of London from 1951 to 1958. Lord Blackford was a successful businessman, becoming Deputy Chairman of the Midland Bank, and Chairman, then Hon. President of the Guardian Assurance Company.