Dharmalingam Siddarthan (Tamil: தர்மலிங்கம் சித்தார்த்தன், romanized: Tarmaliṅkam Cittārttaṉ; born 10 September 1948) is a Sri Lankan Tamil militant turned politician, former provincial councillor and Member of Parliament. He is the leader of the People's Liberation Organisation of Tamil Eelam, a member of the Tamil National Alliance.