Onalaska is located at 30°48′28″N 95°6′24″W / 30.80778°N 95.10667°W / 30.80778; -95.10667 (30.807783, -95.106575). According to the United States Census Bureau, the city has a total area of 2.2 square miles (5.7 km2), of which, 2.1 square miles (5.4 km2) of it is land and 0.47% is water. As of the census of 2000, there were 1,174 people, 538 households, and 350 families residing in the city.