Lomax is a village in Henderson County, Illinois, United States. The population was 454 at the 2010 census, a decline from 477 in 2000. It is part of the Burlington, IA–IL Micropolitan Statistical Area.
Lomax is located in southwestern Henderson County at 40°40′47″N 91°4′20″W (40.679763, -91.072341). Illinois Route 96 passes through the village, leading east 5 miles (8 km) to Illinois Route 94 north of Terre Haute and southwest 6 miles (10 km) to Dallas City along the Mississippi River.
According to the 2010 census, Lomax has a total area of 1.04 square miles (2.69 km2), all land.
As of the census of 2000, there were 477 people, 196 households, and 134 families residing in the village. The population density was 457.3 people per square mile (177.1/km2). There were 213 housing units at an average density of 204.2 per square mile (79.1/km2). The racial makeup of the village was 98.74% White, 0.21% Asian, 0.42% from other races, and 0.63% from two or more races. Hispanic or Latino of any race were 2.73% of the population.