Thirukeethiswaram is a Hindu temple which is located near the town of Mannar, Sri Lanka. It is dedicated to main deity in Shaivism namely Lord Siva and is one of the five ancient Sivan temples around the island.

While tradition has it that Thiruketheeswaram is at least 2500 years old. It has been in existence as an established and famous shrine for at least 1400 years, based on the fact that Nayanmars have sung Thevarams on it. It is associated with the ancient port of entry called Mantotai and may have been built or maintained by merchant guilds from South India. There is epigraphic evidence of maintenance by Pallava and Pandya rulers from India.