The Peel Regional Police force says 34-year-old Shane Campbell was last seen Oct. 14 at the Hilton Hotel at 5875 Airport Road in Mississauga.
Investigators would not say what Campbell was doing in Mississauga but did stress he resides in Calgary.
They say they are concerned for his safety as Campbell requires daily medication, and that it is very out of character for him to disappear.
Campbell is described as white, about 5'7" tall and 200 pounds. He has a medium build, light complexion, short brown hair and blue eyes.
Anyone with information on his whereabouts is asked to call the Peel Regional Police 21 Division Criminal Investigation Bureau at 1-905-453-2121 ext. 2133.
Information can also be left anonymously by calling Peel Crime Stoppers at 1-800-222-8477.