Updated | Missing man and baby back home, safe and well

A man and a baby missing from Sydney's south have returned home and are "safe and well," police say.

"The 39-year-old man and 3-month-old child were last seen on Sir Bertram Stevens Drive, Royal National Park, about 8.15pm Thursday 25 April," a police statement said.

"When they failed to return home and could not be located or contacted, officers attached to Sutherland Shire Police Area Command were notified and commenced inquiries into their whereabouts.

"Following inquiries and an appeal for assistance, they returned home about 6.30am this morning (Friday 26 April).

"Police would like to thanks the media and the community for their assistance."