The company said the workers will receive severance packages and have access to counselling and outplacement services and workshops.
The plant produces branded and private label processed meat.
Premium Brands said it looked at a number of options, but none was economically feasible for the plant, which was built in 1958.
The company plans to gradually move work done at the Toronto plant to other facilities in Ontario starting in the spring, with the final shutdown in December.
Premium Brands owns a range of specialty food and food distribution businesses in Canada and the United States.