Abingdon is a city in Knox County, Illinois, 50 miles (80 km) west of Peoria. It is part of the Galesburg Micropolitan Statistical Area. The city was first settled in 1828 and was incorporated in 1857. In 1894, the patent for the common spring-loaded mousetrap was given to William Hooker of Abingdon, Illinois. In 1890, 1,321 people lived here; in 1900, 2,022; and in 1910, 2,464. The population was 3,612 at the 2000 census.
Abingdon is located at 40°48′13″N 90°24′3″W / 40.80361°N 90.40083°W / 40.80361; -90.40083 (40.803572, -90.400770).
According to the United States Census Bureau, the city has a total area of 1.5 square miles (3.8 km²), all land.