Onattukara (also known as Odanadu, Onadu, Kayankulam and Kallikoilon) is a feudal state in late medieval Kerala.

Onattukara later becomes part of Travancore (after King Marttanda Varma's northern expedition) and is composed of the present day Taluks of Mavelikara, Karthikapally, Chenganur in Alappuzha district and Karunagapally in Kollam district.

Kayankulam is the capital of the Odanadu, which holds an equal position with Venad before the formation of Travancore.

Onattukara is controlled by several Nair lords, among whom the ruler of Kayamkulam is the most prominent.