Sembanarkoil (formerly Semponnarkoil) is a panchayat town in Tharangambadi taluk in Mayiladuthurai district in the Indian state of Tamil Nadu.

Sembanarkoil lies on the shores of Bay of Bengal, comprising a coastal plain with a few sand dunes.

The Northeast monsoon, which starts in October and ends in December, contributes about 60% of the total annual rainfall.

The Southwest monsoon rains from June to September and from March to May account equally for the rest.

The nearest railhead is Mayiladuthurai Junction, which hosts direct trains to Chennai, Bangalore, Mysore, Thirupathi, Bombay, Varanasi, Rameswaram, and Coimbatore.