On February 9, 2017, Smith signed a one-year, $3 million contract with the Toronto Blue Jays. Smith became the Blue Jays setup man early in the season, after Jason Grilli struggled in the role and Joe Biagini was moved to the starting rotation. He was placed on the 10-day disabled list on June 19 with shoulder inflammation. In 38 games, he was 3-0 with a 3.28 ERA in ​35 ⁄ innings.