Vázquez transferred to Canadian club Toronto FC on 20 February 2017. He scored his first goal on 18 March in a 2–0 away win over the Vancouver Whitecaps FC. Throughout his first season in Major League Soccer, he drew praise in the media for adding depth to his new team's attacking play, courtesy of his vision and distribution, and formed a notable partnership in midfield with captain Michael Bradley, who was in turn freed from much of the team's creative responsibilities and played more of a defensive role, while still sharing some of the playmaking duties with the Spaniard; Vázquez's playmaking ability and link-up play with forwards Sebastian Giovinco and Jozy Altidore saw him finish as the second highest assist provider of the regular season (16) while also notching eight goals, as Toronto captured the Canadian Championship followed by the Supporters' Shield for most points in the league, after a 4–2 home win over New York Red Bulls on 30 September in which he scored from an injury time penalty.