Somasundaram Senathirajah (Tamil: சோமசுந்தரம் சேனாதிராஜா Sinhala: මාවෙයි සේනාධිරාජා) born 27 October 1942; commonly known as Mavai Senathirajah) is a Sri Lankan Tamil politician and Member of Parliament. He is the current leader of the Illankai Tamil Arasu Kachchi (ITAK), a member of the Tamil National Alliance (TNA).