Founded in 1877 and maintained by the Department of National Museums, it holds collections of significant importance to Sri Lanka, such as the regalia of the Kandyan monarchs, as well as many other exhibits relating the country's cultural and natural heritage.

[3] The Royal Asiatic Society was instrumental in bringing to the notice of Gregory on his appointment as governor in 1872 the need for a public museum, with some difficulty the approval of the legislative council was obtained within a year.

The Government architect of the Public Works Department, James George Smither (1833–1910)[3] was able to prepare the plans for a new structure in the Italian Architectural style.

[citation needed] In January 1877, the completed building of the Colombo Museum was declared open by Governor Gregory, in the presence of a large crowd, amongst which there were many Muslims.

He asked the same question of the carpenter S. M. Perera who was responsible for the woodwork of the museum, who requested and was awarded a local rank.

[5] The crown jewels and the throne of the last King of Kandy, which were returned to Sri Lanka by the British Government, were added to the museum collection.

From its inception, special attention was given to building up of a collection related to Sri Lanka, Orientation and Natural Science.