Mansbridge is originally from Ottawa and there attended Glebe Collegiate Institute. He was not a very successful student and only got a job at CBC when a producer was at the Macdonald-Cartier Airport in Ottawa and heard an P.A. announcer with a very good voice. The announcer was Mansbridge, he was hired to work for the CBC and gradually worked his way up through the ranks to become a prominent reporter, and then finally main anchor of the CBC news, replacing Knowlton Nash.
Mansbridge's personal life has long been a tabloid staple. He was married to Wendy Mesley, a CBC reporter, for many years before getting a divorce and marrying Cynthia Dale, a star of Street Legal. Mansbridge and Dale currently live in Stratford, Ontario.