Juli was last seen on 3 Sept in the Bentleigh area.
Police have concerns for her welfare due to her age and the length of time she has been missing.
Juli is 150cm tall with a thin build, and currently has black hair.
At the time she went missing, Juli was wearing black leggings, a black hoodie and black runners.
She may have travelled to the Melton area.
Anyone with information about Juli is asked to contact Caulfield Police Station on (03) 9524 9500.