Chandrabhanu (died 1262) or Chandrabhanu Sridhamaraja was the King of Tambralinga Kingdom in present-day Thailand, Malaysia and Sumatra and the Jaffna Kingdom in northern Sri Lanka. A Javaka, he was known to have ruled from during the period of 1230 until 1262. He was also known for building a well-known Buddhist stupa in southern Thailand. He spent more than 30 years in his attempt to conquer Sri Lanka. He was eventually defeated by the forces of the Pandyan Dynasty from Tamil Nadu (in present-day South India) in 1262 and was killed by the brother of the south Indian Emperor Jatavarman Sundara Pandyan.

In 1247 he sent an expedition to the island ostensibly to acquire the Buddhist relic from the island.^{: 184–185} Sinhalese King Parakramabahu II sent his nephew Prince Veerabahu to handle the unexpected Malay invasion. He was able to defeat Chandrabhanu. But Chandrabhanu's forces, using poison darts, were able to occupy the Jaffna kingdom, the northern part of the island in 1255. Repeated attempts to conquer the rest of the island ensued. In 1258 his forces faced an invasion of the island by the forces of the Pandyan Dynasty commanded by Jatavarman Sundara Pandyan I, and Chandrabhanu submitted to Pandyan rule, bringing the Jaffna kingdom under Pandyan suzerainty. From 1262-1264 Tambralinga forces, using Chola and Pandyan soldiers commanded by Chandrabhanu's son Savakanmaindan and two Sinhalese princes were defeated by the Pandyans led in the invasion by Jatavarman Vira Pandyan I. In 1270, Savakanmaindan, kept on the Jaffna throne under Pandyan suzerainty attempted to invade the south of the island once again, and was defeated decisively by the Pandyans under Maravarman Kulasekara Pandyan I by the late 1270s. The defeat was so complete that in 1290, Tambralinga was absorbed by the neighboring Thai Kingdoms.