Thenmuli Rajaratnam was the assassin who killed Rajiv Gandhi, herself, and 16 others in a suicide bombing on May 21, 1991, in the Indian town of Sriperumbudur, near Madras.

An associate of the The Liberation Tigers of Tamil Eelam (the Tamil Tigers), Rajaratnam was also known as Dhanu.

Gandhi was campaigning in Tamil Nadu for upcoming parliamentary elections when the bombing occurred. The last time Gandhi had been in power, he had sent Indian troops into Sri Lanka to help enforce a peace accord, and the Tamil Tigers wanted to keep him from doing it again. The troops he had sent in 1987 had fought the Tamil separatist guerrillas and harassed many Tamils. Rajaratnam's personal motivation for becoming a suicide bomber stemmed from her rape by Indian soldiers during that time.

Rajaratnam had the belt bomb with the explosive material in her lower back region and the power pack, two switches and the circuitry in front. One switch initiated the circuitry and the other activated the bomb. The explosive used was an RDX, or Research Department Explosive; about 10,000 2 mm steel balls were embedded in the bomb. After garlanding Gandhi, Rajaratnam evidently stooped to touch his feet and activated the explosive. Rajiv Gandhi must have tried to stop her; his face bore the impact of the blast.

Seven years later, an Indian court convicted twenty-six people in the conspiracy to assassinate Gandhi.