The turtle, 60 centimetres long and weighing 20 kilograms, is estimated by a researcher from Phuket Marine Biological Center (PMBC) to be about 10 years old.
It was discovered in poor condition, gaunt and pale, possibly as a result of swallowing a plastic bag. Turtles frequently swallow plastic bags, mistaking them for jellyfish, their main food.
The turtle was taken to the PMBC for care until it is strong enough to be returned to the sea.
It is the third turtle to have washed up on Phuket’s shores in the past six weeks.