The San Jorge Gulf is a bay in southern Patagonia, Argentina. It is an ocean basin opening to the Atlantic. Its shoreline spans Chubut and Santa Cruz province. The gulf measures approximately 229 km at its mouth and covers approximately 39 km². It is located between Cape Dos Bahías and Cape Tres Puntas.
Due to its geography, more than 70% of the gulf's basin is between 70 metres and 100 metres deep. To the south it is about 50 metres 60 metres deep and in the north 90 metres. The seabed was formed by bivalves and cirripedial remains, and it consists of mud, sand, gravel, and sand with carbonate.
The mean water temperature varies between 5.09 °C and 13.41 °C, salinity is around 33000 ppm.
Approximately 90% of Chubut Province's inhabitants live on the coast of the gulf. Comodoro Rivadavia and Caleta Olivia are two larger cities along the coast. Each having ports with oil buoys and fishing facilities.
The fishing towns of Camarones and the seaside resort Rada Tilly also lie along the gulf.