Dehiwala-Mount Lavinia is a large municipality in Sri Lanka with a population of 245,974 as of 2012. Covering an area of 2,109 hectares, it is situated south of the Colombo Municipal Council area. The northern boundary of the municipality is defined by the Dehiwala canal, while its southern limits lie at Borupana Road and its eastern boundary is marked by Weras Ganga and its canal system.
The area has undergone rapid industrialization and urbanization due to residential and commercial overspill from Colombo. Together with Sri Jayawardenapura Kotte, Dehiwala-Mount Lavinia functions as a major suburban center within the Colombo Metropolitan Region's core urban area. The towns are located along the Galle Road artery, which runs along the southern coast of the country.
Notable landmarks in the municipality include the National Zoological Gardens, which is one of the largest in Asia, and the Colombo South Teaching Hospital. The region also contains the Ratmalana airport. Dehiwala and Mount Lavinia are characterized by their significant role in the urban agglomeration of the capital city.