A fairly large suburb bordering Colombo, Rajagiriya lies between Borella and Ethul Kotte, straddling Parliament Road.

The area was originally known as Welikada and stretched from the Ethul Kotte bridge to the tram terminus at Borella.

[2] The area developed because of plumbago, which was shipped up the canal network from Ingiriya in the Kalutara district for purification at the Welikada graphite works.

In the late 1970's, The Government of JR Jayawardene ran a major road through the very middle of the EW Perera Park (which commemorated a national hero and was the venue for Football, Cricket and other sports).

The Sri Jayawardenapura Kotte municipal ward of Rajagiriya is confined to the areas around the original grounds of the Governor's house.