The shooting began inside the Muzik nightclub and spilled out onto the streets just before 3:30 a.m., Toronto Police Superintendent Frank Bergen told local TV station CP24.
The club was the site of a party following the OVO Fest, an annual music festival, which is also run by the Canadian-born Drake, 28.
The venue was packed with many people in their 20s and 30s. It's not clear whether Drake was inside during the shooting.
Drake brought up the controversy between himself and Meek Mill, 28 – who accused the rapper of not writing his own lyrics – before closing out the OVO Fest on Monday night by including guests Kanye West, Pharrell Williams, Future and Travi$ Scott in a performance using memes to poke fun at Mill.
It was a busy Monday for the Grammy-winning artist: In addition to performing, Drake also unveiled and modeled a new uniform for the Toronto Raptors basketball team.
This is the second consecutive year violence has plagued the OVO Fest.
A shooting outside the same club in 2014 left one man injured, the Toronto Star reports.
A phone call and email to Drake's agent were not immediately returned on Tuesday.