The deal lasts until 2018.
Bath supporters will see the team line up in the new Canterbury kit for the first time on September 12, when they take on Gloucester at the Memorial Ground in the inaugural West Country Challenge Cup.
Canterbury CEO Chris Stephenson says: “We are excited to announce our three-year deal with Bath Rugby in their 150th anniversary year.
“By joining with Bath, a club steeped in rugby history and values, Canterbury demonstrates their commitment to the game and continued desire to partner with the very best teams in the world.
“We are delighted with this partnership and hope supporters look forward to our involvement with the club.”
