John Wesley Brien (November 24, 1864 - January 11, 1949) was a Canadian politician and physician.

Prior to his federal political career, he had just served a year in the Canadian Expeditionary Force as a medical officer before being forced to return home due to injury.

He also served as a captain in the British Canadian Recruiting Mission in Chicago, Illinois, United States of America.

Brien was born in Victoria County, Canada West.

His cousin, James Brien, was also a Member of the House of Commons of Canada.