Paul Gross is the elder of two brothers. He was an Army brat; his father, Bob Gross, was a Tank Commander in the Canadian Army. As a consequence Paul and his family moved around a lot: he has lived in Canada, the U.S, England and Germany. Paul was introduced to acting in his early teens, while the Gross family was in Washington. He performed in stage plays such as Canterbury Tales and Faustus. From the age of 14, he appeared in television commercials, which enabled him to pay for his degree in Drama at the University of Alberta in Edmonton.

In 2011, Paul Gross appeared at the Royal Alexandra Theatre in Toronto playing Elyot opposite Kim Cattrall's Amanda in the celebrated comedy by Noel Coward, Private Lives.