Gaasinather Gangaser Ponnambalam (Tamil: காசிநாதர் காங்கேசர் பொன்னம்பலம்: 12 August 1938 – 5 January 2000; known as Kumar Ponnambalam) was a Sri Lankan lawyer and politician. Leader of the All Ceylon Tamil Congress, he was a presidential candidate in 1982. He was shot dead in January 2000 in an assassination many suspect to be ordered by President Chandrika Kumaratunga.