The Postgraduate Institute of Archaeology (PGIAR) was established on the 1st January 1986, by order dated 18th December 1985, under section 24A of the Universities Act No. 16 of 1978 by the University Grants Commission. The PGIAR is a Postgraduate Institute of the University of Kelaniya. It is the prime institution for postgraduate studies and research in archaeology and subjects related to archaeology in the country.
The PGIAR is housed at 407 Bauddhaloka Mawatha, Colombo 7 in a historic building originally used as a Government Residence for public officers. Currently it has four units of buildings including the historic building. A new three-storey building was built in 2009 with sufficient space for teaching and faculty offices. Administration and most of the laboratory work are carried out in two single storey temporary buildings.