A member of the public reported locating the baby in the yard of their home on Copernicus Way in Keilor Downs shortly before 8am on Thursday morning.
The baby and a woman from a nearby address were taken to hospital for treatment. Both remain in stable condition at Western Health Sunshine.
Victoria Police have commenced an investigation into the discovery. The circumstances surrounding how the newborn came to be in the backyard remain under examination.
Cases involving abandoned or discovered infants raise questions about access to support services and safe options for parents in crisis. Across Australia, women facing pregnancy in difficult circumstances can seek confidential assistance at hospitals and through community health services without risk of automatic legal sanction, though the legal framework varies by state and territory.
Anyone with information about the incident is urged to contact Crime Stoppers on 1800 333 000 or visit the website.
For those seeking immediate support, Lifeline Australia is available on 13 11 14, and Beyond Blue offers support for mental health concerns. In the event of an emergency, dial Triple Zero (000).