The celebrations marked the end of Holy Muslim month of Ramadan, spent by fasting.
Young and old congregated in mosques to offer prayers across the state, including at Chennai, Tiruchirappalli, Perambalur, Erode and Karur, among others.
They also exchanged pleasantries with each other.
Earlier, Tamil Nadu Governor K Rosaiah, Chief Minister J Jayalalithaa, DMK President M Karunanidhi and other leaders had extended their Eid greetings.