Stanbridge was born in Worth Parish, Sussex, England and came to western Canada in 1903. He operated an insurance and real estate business in Winnipeg and then, in 1912, became the owner of a meat-packing plant in Stonewall. Stanbridge served 15 years on the school board for Stonewall. He married Frances Rudderham.
He was elected to the Manitoba legislature in the 1920 provincial election as a Labour Party candidate in the St. Clements constituency. He defeated Liberal incumbent Donald A. Ross by 127 votes, and sat with the Labour parliamentary group in the legislative opposition for the next two years.
The Labour Party and its allies won eleven seats in the 1920 election, which occurred shortly after the Winnipeg General Strike of 1919. Their support had declined by the time of the 1922 election, and fell to six seats. Stanbridge, running for the Independent Labour Party in St. Clements, finished fourth in a field of four candidates in his bid for re-election.
He died in Winnipeg General Hospital at the age of 63.
- "Matthew James Stanbridge (1876-1939)". Memorable Manitobans. Manitoba Historical Society. Retrieved 2012-01-05.|
- "M. Stanbridge, Ex-MLA, Dies". Evening Tribune. Winnipeg. May 23, 1939. p. 2. Retrieved 2012-01-05.
- "MLA Biographies - Deceased". Legislative Assembly of Manitoba. Archived from the original on 2014-03-30.