It is situated on the Galle–Colombo (Galle road) main highway, 18 km (11 mi) south of the centre of Colombo.

Moratuwa is surrounded on three sides by water, except in the north of the city, by the Indian Ocean on the west, the Lake Bolgoda on the east and the Moratu river on the south.

[1] Moratuwa is the birthplace of Veera Puran Appu, a resistance fighter against British rule in Matale, the philanthropist Sir Charles Henry de Soysa and the musician Pandit W. D. Amaradeva.

Moratuwa consists of 24 main areas: Angulana, Borupana, Dahampura, Egoda Uyana, Idama, Indibedda, Kadalana, Kaduwamulla, Kaldemulla, Katubedda, Katukurunda, Koralawella, Lakshapathiya, Lunawa, Molpe, Moratumulla, Moratuwella, Puwakaramba, Rawathawatta, Soysapura, Thelawala, Uswatta, Uyana and Willorawatta.

[2] Both Moratuwa and Lakshapathiya are mentioned in the 15th century poem Kokila Sandesha, written by a monk poet of Devundara to celebrate Prince Sapumal during the reign of King Parakramabahu VI.

[3][4] Lunawa, Uyana and Rawathawatte are mentioned in 16th century chronicles and church records of martyrs, the latter commemorates Revatha Thera, the chief incumbent of a temple built by King Vijayabahu I.

And as the sea in this quarter abounds in fish, and this lagoon has many arms leading from its ample basin into canals stretching along the coast, and into rivers, flowing from the mountains, so as to form a great harbour, the surrounding country, which is very fertile, has become very populous.

On the bank of land referred to, stands the thriving village of Morotto, remarkable for its fishermen and its carpenters.

Industries in Moratuwa include the manufacture of furniture, rubber products, batteries, transformers, and wood handicrafts.

It is a tributary of the Kalu Ganga which originates at Adam's Peak and is a popular resort for swimming, angling and boating.