An official said the monk’s body was found inside a Buddhist temple, BBC reported.
Police said Maung Shue U Chak appeared to have been attacked by at least four people at the temple in Baishari, 350 km south-east of the capital Dhaka.
His killing follows the murder of two prominent gay activists, a law student and a university professor in April.
In February, a Hindu priest was beheaded in northern Bangladesh.
More than 20 people have been killed by suspected Islamists in the last three years.