Police are appealing for public assistance to help locate missing girl Sienna Johnson.
The 11-year-old was last seen leaving her residence in Manor Lakes on Tuesday evening about 11.30pm.
Police have concerns for her welfare due to her age.
Sienna is about 130cm tall with a thin build, brown eyes and has fair/blonde hair.
It is not known what she was last wearing.
Police have released an image of Sienna in the hope someone recognises her and can provide information on her whereabouts.
She is known to frequent the Watsonia, Fawkner and Geelong areas.
Anyone who sights Sienna or who knows of her whereabouts is urged to contact Werribee Police Station on 9742 9444.