Kalyanasundaresar Temple, Nallur (கல்யாணசுந்தரேஸ்வரர் கோயில், நல்லூர்) or Thirunallur is a Hindu temple dedicated to the deity Shiva, located in Nallur, in the outskirts of Kumbakonam in Tamil Nadu, India. Shiva is worshiped as Kalyansundaresar, and is represented by the lingam. His consort Parvati is depicted as Girisundari. The presiding deity is revered in the 7th century Tamil Saiva canonical work, the Tevaram, written by Tamil saint poets known as the nayanars and classified as Paadal Petra Sthalam. The legend of the temple is associated with sage Agastya and Amaraneethi Nayanar, one of the 63 nayanars, the Tamil Saiva saints. The lingam in the temple is believed to change colours five times during the day time.