Trinity Ewing, 15, of Lakeview Park Avenue in Oshawa was last in touch with her family on July 11 at 10 p.m.
She has left for periods of time before, and her family is concerned for her well-being and are trying to contact her.
She was last seen with a friend at the Uxbridge Library on Friday, July 12.
Repeated attempts to locate her have been unsuccessful. It is believed she is in the Uxbridge area.
Ewing is described as a white female, 5’11”, about 170 lbs, with a slender build, light complexion, blue eyes, and short, wavy hair often dyed with bright colours.
She was last seen wearing black shorts and a green tube top.
Anyone aware of Ewing’s location is asked to contact their local police service. In Durham Region, call 1-888-579-1520.