Hilliard is a city in Franklin County, Ohio, United States. The population was 28,435 at the 2010 census.
Hilliard is located at 40°2′4″N 83°8′34″W / 40.03444°N 83.14278°W / 40.03444; -83.14278 (40.034310, -83.142678). It is bordered on the east by Upper Arlington, on the north by Dublin, on the south by Galloway and Columbus, and to the west lies open farmland. Downtown Columbus lies in a distance to the southeast, its skyline visible at times when crossing bridges. The only major highway that runs through Hilliard is I-270, which runs north and south slightly east of the middle of the city.
According to the United States Census Bureau, the city has a total area of 11.1 square miles (28.9 km²), all of it land.