The 1991 Canadian Open was a tennis tournament played on outdoor hard courts. It was the 102nd edition of the Canada Masters, and was part of the ATP Super 9 of the 1991 ATP Tour, and of the Tier I Series of the 1991 WTA Tour. The men's event took place at the Uniprix Stadium in Montreal, Canada from July 22 through July 28, 1991, and the women's event at the National Tennis Centre in Toronto, Canada from August 5 through August 11, 1991.
Andrei Chesnokov def. Petr Korda, 3–6, 6–4, 6–3
- It was Andrei Chesnokov's 1st title of the year and his 7th overall. It was his 1st Masters title of the year and his 2nd overall.
Jennifer Capriati def. Katerina Maleeva, 6–2, 6–3
- It was Jennifer Capriati's 2nd title of the year and her 3rd overall. It was her 1st Tier I title.
Patrick Galbraith / Todd Witsken def. Grant Connell / Glenn Michibata, 6–4, 3–6, 6–1
Larisa Savchenko-Neiland / Natalia Zvereva def. Claudia Kohde-Kilsch / Helena Suková 1–6, 7–5, 6–2