Cudmore says he "had a bit of trouble growing up". As a teenager he was an enforcer for a drug dealer in his home town and spent a year in a youth detention center following a conviction for assault. He has stated that rugby turned his life around.
Cudmore's younger brother is actor Daniel Cudmore, who starred as the mutantColossus in the X-Men films. His other younger brother, Luke Cudmore, has represented the Canada U21 rugby team.
Jamie Cudmore is married to Jennifer Cudmore, originally from Newfoundland, and they have a daughter, Maelle. They currently live in the Clermont-Ferrand area of France, where Jamie owns a wine bar called "Vinomania", and a sportsbar/nightclub called "The Five". Jamie's wife is an entrepreneur with an honors MBA from Grenoble École de Management, and together they recently came out with their own wine label called "Sin Bin". With the Chardonnay being named 'Yellow Card', and 'Red Card' being the name of the Pinot Noir Gamay, they poke fun at his disciplinary record.