South Elgin is located at 41°59'39" North, 88°17'30" West (41.994167, -88.291944).
According to the United States Census Bureau, the village has a total area of 6.41 mi2 (16.60 km2). 6.29 mi2 (16.29 km2) of it is land and 0.12 mi2 (0.32 km2) of it is covered by water. The total area is 1.92% water.
South Elgin is located in the Central Standard Time (CST) timezone, GMT-06:00. It observes Daylight Saving Time (DST).