Lanka Matha Mother Sri Lanka Capital Sri Jayawardenapura Kotte [1] [2] 6°54′N 79°54′E Largest city Colombo Official language(s) Sinhala Tamil Demonym Sri Lankan Government Unitary republic Democratic Socialist Semi-presidential system  -  President Mahinda Rajapaksa  -  Prime Minister D. M. Jayaratne  -  Speaker of the House Chamal Rajapaksa  -  Chief Justice Dr.