Thushantha Mahendra Ratwatte is a Sri Lankan politician and former Mayor of Kandy. Currently, he serves as the Basnayake Nilame of Sri Maha Vishnu Devalaya of Kandy & Dedi Munda Devalaya of Aluthnuwara. He is the son of former Sri Lankan Deputy Defense Minister Anuruddha Ratwatte.

Ratwatte was born in Kandy as the second son of General Anuruddha Ratwatte & Carman Rangala Ratwatte. Ratwatte's father was an acting Diyawadana Nilame and former Cabinet Minister. His grandfather Harris Leuke Ratwatte was former Diyawadana Nilame of Sri Dalada Maligawa, Kandy. He has two brothers, former state minister Lohan Ratwatte and businessman Chanuka Ratwatte. He was educated at Trinity College, Kandy.

Ratwatte entered active politics from Sri Lanka Freedom Party in 2011 and was elected to the Kandy Municipal Council. He served as the Mayor of Kandy, from 2011 to 2015.

His son Dinuk Ratwatte is also a politician.