The Department of Socialogy at Peradeniya is the largest and the best-known Sociology Department in the University system in Sri Lanka. It was established in 1947. Since its establishment, the Department of Sociology grew in its reputation, academic achievement and research output. Initially the student number was deliberately kept low, but since the 1970s the enrollments increased, following the introduction of Sociology in Sinhala and Tamil media. At present, the Department of Sociology is one of the largest departments in the Faculty of Arts with well over 1000 students following Special and General degree courses. The department teaches in English, Sinhala and Tamil media and caters to a diverse student population drawn from all parts of the country. This is the only Sociology Department within the whole university system in Sri Lanka that teaches in all three media and, therefore, fully representative of the ethnic and socio-cultural diversity in the country
Among the pioneering sociologists associated with the Department were the Prof.Bryce Ryan, Prof.Ralph Pieris, Prof.S.J. Tambiah, Prof. Gananath Obeyesekere, Prof.Laksiri Jayasuriya, Prof. Nur Yalman, Prof. E.R. Leach, Prof. H.L.Seneviratne and Prof. Kitsiri Malalgoda. Prof. K. Tudor Silva, Emeritus Prof. W. M. Sirisena and Prof. M. W. Amarasiri De Silva another prominent members who have served in the Department in the recent past.