The Pusweli Oya is a major tributary of the Kelani Ganga river in Sri Lanka.

Starting from the hills in Puswelihena in Horana Division of Kalutara District, it flows northwards through a low-lying flat land (6–10 meters above sea level) converted into rice fields, which ultimately becomes the stream's flood plain during rainy seasons.

On its way, the stream is joined by the Ma Dola starting from the hills of Madoluwawa and Kurugala, the Angomuwa Oya starting from Angomuwa and Miriyagal Kanda and the Arukwathu Oya starting from Udagama Kanda (1492 feet above sea level).

The stream flows for 16 km down its valley before joining the Kelani Ganga near Hanwella.

This article related to a river in Sri Lanka is a stub.