Udaiyanachi is a village in Kallakkurichi tehsil in district of Viluppuram, Tamil Nadu, India. As per the data provided by Census of India in 2011, total population of Udaiyanachi was 2,233 which includes 1,126 males and 1,107 females. Udaiyanachi covers 662.83 ha area. Pincode of Udaiyanachi is 606203.