At around 6:30 a.m. environmental workers at Bai Truoc beach in Vung Tau City spotted the dead turtle carried in by the waves, and used wooden beams to carry it ashore with the help of people at the beach.
The adult is thought to have died several days earlier, and had a long crack running along its shell.
"It is likely that a propeller from a vessel caused the turtle's death," a forest protection employee speculated.
Ba Ria-Vung Tau authorities are planning to bury the reptile.
The olive ridley sea turtle (Lepidochelys olivacea) is classified as vulnerable in the IUCN Red List of Threatened Species.
The province’s Con Dao Island is almost the only breeding ground for the turtle in Vietnam.
Nearly 700 of the turtles are spotted coming to the island to lay eggs every year.