Kolathiri or Kolathiri Rājā (King of Kolathunādu) was the title by which the senior most male along the matrilinieal line of the Mushika or Kolathunādu Royal Family (Kolaswarũpam) was styled. The Mushika Family came to be known as Kolathiri over the centuries, and were directly related to, and descended from the Cheras, Pandyas, Cholas and the Ay (subsequently known later as the Venad and much later the 'Thiruvithamkur' Royal Family) originating in the Thiruvananthapuram area. The Kolathiri would have started out as a branch of the Cheras and the Ay in the period it was known as Mushika. They had their seat at Ezhimala in Kerala, India and was one of the major political houses which became completely independent and prominent in Kerala, after the disappearance of the imperial Kulasekharas or Perumāl rulers of Mahodayapuram by the twelfth century AD. The Kolathiri and the Thiruvithamkur reciprocally adopted girl-children from each other for several centuries right into the 1990s.
"Kolathiri" appears as a character in a Malayalam film titled Urumi. The film is based on a fictional story about a young Indian who tried to kill Vasco da Gama. The movie was released on 31 March 2011.
- Duarte Barbosa, The Book of Duarte Barbosa: An Account of the Countries Bordering on the Indian Ocean and their Inhabitants, II, ed.M. L Dames (repr., London: Hakluyt Society, 1921)
- The Dutch in Malabar: Selection from the Records of the Madras Government, No. 13 (Madras: Printed by the Superintendent, Government Press, 1911), 143.
- Perumals of Kerala by M. G. S. Narayanan (Calicut: Private Circulation, 1996)