Koswatta Ralalage Udayakantha Gunathilaka (born 3 May 1965) is a Sri Lankan politician, former provincial councillor and Member of Parliament.
Gunathilaka was born on 3 May 1965. He was a member of Warakapola Divisional Council and the Sabaragamuwa Provincial Council. He contested the 2020 parliamentary election as a Sri Lanka People's Freedom Alliance electoral alliance candidate in Kegalle District and was elected to the Parliament of Sri Lanka.