Police say Edith Gus, 72, was last seen around 1 p.m. on Monday walking toward G. Ross Lord Park, which is located off Finch Avenue West between Dufferin and Bathurst streets.
Police have set up a command post in the park.
Gus is described as white, five feet tall with a medium build and brown hair. She walks leaning to the right.
She was last seen wearing a bright-red jacket, brown large-framed sunglasses, brown pants and brown shoes.
Police say she does not speak English and answers only her name, which is pronounced "Eee-dit."