The topography of Villianur is characterized by flat, low-lying coastal plains, typical of the Puducherry region. The average elevation is approximately 24 meters (79 feet) above sea level.
There are no mountains, significant hills, or deep valleys within the commune. The terrain gently slopes towards the Bay of Bengal to the east. The primary topographical variations are formed by the banks and floodplains of the Sankaraparani River, as well as a network of ancient irrigation tanks and man-made canals that crisscross the agricultural landscape.