Villamiroglio borders the following municipalities: Cerrina Monferrato, Gabiano, Moncestino, Odalengo Grande, and Verrua Savoia.
Its municipal borders enclose an area of 17.1 km², which ranges in altitude between 158 and 422 metres above sea level, and touch Gabiano to the north, Mombello Monferrato to the east, Castelletto Merli and Odalengo Piccolo to the south, and Odalengo Grande and Villamiroglio to the west.