Paxton, who's from British Columbia, pointed to a tattoo on his right forearm of a maple leaf - a national symbol - as he celebrated to a standing ovation at Rogers Centre.
Paxton cruised through most of the game, with two walks in the third inning his only real blemish.
Paxton struck out 16 batters in his previous outing, a no-decision against Oakland.
It's also reportedly the first no-hitter thrown by a Canadian in Canada.
Coming into this game, there had been a number of Seattle Mariners rumors about Ichiro Suzuki [VIDEO] and his future with the team. Nelson Cruz knocked in the Mariners' second run with an RBI single in the same inning.
Russell Martin led off the Toronto eighth with a long drive that left fielder Ben Gamel caught near the wall.
Robinson Cano put the Mariners on the board offensively, bringing in Gamel on an RBI ground out in the top of the third inning. Mitch Haniger brought in the Mariners' final run on a sacrifice fly in the fifth inning.
NOTES: Attendance was 20,513.
It was the first no-hitter against the Blue Jays since Detroit's Justin Verlander did it in Toronto on May 7, 2011. The Blue Jays placed shortstop Aledmys Diaz on the 10-day disabled list (retroactive to Monday) with a left ankle sprain. Sebastian Toutant, the Pyeongchang Olympic gold medallist in snowboard big air, threw out the ceremonial first pitch to fellow Canadian and Blue Jays outfielder Dalton Pompey.