James Arthur Mathewson (June 26, 1890 – August 23, 1963) was a Canadian politician.
Born in Montreal, Quebec, Mathewson received a Bachelor of Arts degree in 1912 and a Bachelor of Civil Law degree in 1917 from McGill University.
He was called to the Quebec Bar in 1917.
He was a captain in the 42nd Battalion Royal Highlanders of Canada during World War I.