The Shepparton toddler was last seen in Shepparton over a week ago, on Monday, February 10.
Police and family have concerns for her welfare due to her age and the length of time she’s been missing.
Investigators believe Billy is in the company of 42-year-old Julie Commisso and may have travelled to the Footscray area.
Police have released images of Billy and Julie in the hope that someone may be able to provide information on their current whereabouts.
Anyone who sees Billy or Julie is urged to contact Footscray Police Station on (03) 8398 9800 or Crime Stoppers on 1800 333 000.
