The 29-year-old Czech, who won the Rogers Cup in 2012, initially injured her forearm while training in Paris ahead of the French Open and has not competed since her loss in the last 16 at Wimbledon last month.
"My forearm injury is continuing to cause some problems so, on the advice of my medical team, I have made the decision not to travel to Canada," Kvitova said in a Tennis Canada news release. "I will really miss being in Toronto this year."
Australian Open
When is the Australian Open draw? Who could Djokovic face?
12/01/2022 AT 13:28
The injury has interrupted what has been an impressive season for Kvitova, who triumphed in Sydney, finished runner-up at the Australian Open and then won the title in Stuttgart.
Kvitova was among the favourites going into the French Open but withdrew from the year's second Grand Slam before her first-round match because of the forearm injury that she said at the time required her to take up to three weeks off.
Due to Kvitova's withdrawal from Toronto, Tennis Canada said three-times champion Serena Williams will now be a top-eight seed and play her opening match on Wednesday.
Australian Open
Australian Open 2022 - Who's playing, when's the draw, what's the schedule
10/01/2022 AT 14:15
Australian Open
Serena and Venus to miss Australian Open for first time since 1997
05/01/2022 AT 12:57