The company says the plant will be shut down in March 2016.
Wrigley says those affected will be offered severance package, career transition support and paid time to attend other job interviews and counselling.
All production from the Toronto plant will be shifted to its facility in Gainesville, Ga.
In a statement, Wrigley says the closure is due to declining gum sales over the past few years.
It adds that the company's Canadian head office, which employs 1,200 people, will remain in Toronto.
Ontario's economic development minister, Brad Duguid, issued a statement saying officials of Wrigley parent company Mars Inc. had assured the province that "they remain committed to their other Ontario business operations," including production facilities in Bolton, Guelph, and Newmarket.