Waterloo is located in southwestern Illinois in Monroe County (of which it is the county seat) about 15 miles south of St Louis along Highway 3 about 10 miles east of the Mississippi River. The population estimate for July 1, 1998 was 6,331, an increase of 1,301 since 1990.
Area golfers enjoy their outings at Acorns Golf Links, Annbriar Golf Course and The Ridge Golf & Country Club on Ridge Rd.