Lynda Moussadji was last seen on Thursday around 4 p.m.
Her family and police are concerned for her safety. The 63-year-old woman was last seen leaving work in Unionville, but she left behind her purse and cellphone at the school. Her family noted it was unusual behaviour.
Moussadji is described as white, five-feet-two inches tall with a heavy build, short reddish-brown hair with bangs, and was last seen wearing a three-quarter length blue jacket with light-coloured pants.
York Regional Police have set up a command post at 300 Main Street. Anyone who sees Moussadji is asked to contact police at 1-866-876-5423 ext. 7541, or to call Crime Stoppers anonymously at 1-800-222-TIPS.