The Barker Inlet is a tidal inlet of the Gulf St Vincent in Adelaide, South Australia, named after Captain Collet Barker who first sighted it in 1831. It contains one of the southernmost mangrove forests in the world, a dolphin sanctuary, seagrass meadows and is an important fish and shellfish breeding ground. The inlet separates Torrens Island and Garden Island from the mainland to the east, and is characterised by a network of tidal creeks, artificially deepened channels, and wide mudflats. The extensive belt of mangroves are bordered by samphire saltmarsh flats and low-lying sand dunes.

Collet Barker was a British military officer and explorer. He explored areas of South Australia, Western Australia and Cobourg Peninsula, Northern Territory.