According to the U.S. Census Bureau, South Jacksonville has a total area of , of which , or 2.29%, are water. Mauvaise Terre Creek flows northward through the east side of the village, passing through Mauvaise Terre Lake, a reservoir. The creek is a tributary of the Illinois River.
According to the US Census Bureau South Jacksonville has a total area of  of which  or 229% are water Mauvaise Terre Creek flows northward through the east side of the village passing through Mauvaise Terre Lake a reservoir The creek is a tributary of the Illinois River