It was originally the sitio of Anahaw founded by immigrants from the municipality of Bacuag.

Sitio Anahaw was situated near Lake Mainit, and would often be flooded due to heavy rains.

During rainy seasons, the local families transferred to a place now called Alegria.

Its name was given by Judge Sixto Olga who happened to spend a night in the place.

Because their affair was lively he told the people to change the name Anahaw to Alegria.