Toronto police say an RCMP handgun and multiple magazines were stolen at Sherway Gardens.
The gun, a Smith & Wesson 9mm pistol, was inside a black satchel when it was stolen, police said.
The bag was hanging off the back of a chair when it was stolen. It also contained three magazines and a police radio.
Investigators believe the theft happened sometime between 7:30 p.m. and 9:45 p.m. on Wednesday, Oct. 30.
Police have been investigating the theft since that evening but are now asking for assistance from the public.
They are asking anyone who finds the satchel to call 9-1-1 and to not remove the gun from the bag.
Anyone with information about the theft is also asked to call police or Crime Stoppers anonymously.