Paul Quantrill
In the current landscape of Canadian MLB talent, I think that Paul Quantrill tends to get forgotten. He played for the Blue Jays during the playoff drought amidst a stretch of post-World Series mediocrity. Despite this, following a failed 1996 season as a starter, Quantrill became one of baseballs’ most reliable bullpen arms.
From 1997 to 2001, the London, Ontario native posted a 3.05 ERA in 383.1 innings and had the best ERA among all MLB relievers with at least 380 innings pitched. He may have never been a closer or a big-name pitcher, but Quantrill is the best Canadian-born pitcher in franchise history, and it isn’t particularly close.