The 17-year-old was last seen in Little Bourke Street, in Melbourne’s CBD about 4pm on Sunday 23 August.
Alisha is about 180cm tall, with a thin build and black hair.
She is known to spend time in the Geelong CBD, Richmond, South Melbourne, Melbourne CBD and Corio.
Police hold concerns for her welfare due to her age.
Anyone who sees Alisha should call Geelong Police Station on (03) 5225 3152.