Vishnampettai is a village in Thiruvaiyaru tehsil in district of Thanjavur, Tamil Nadu, India. As per the data provided by Census of India in 2011, total population of Vishnampettai was 2,655 which includes 1,314 males and 1,341 females. Vishnampettai covers 607.52 ha area. Pincode of Vishnampettai is 613105.