Gages Lake is a census-designated place located in the U.S. state of Illinois. It is within Lake County in Warren Township. It has a total area of 3.3 square miles at 42°21′07″N 87°58′59″W. The elevation is 774 feet above sea level. As of the 2010 census data, it had a total population of 10,198. The population density was 3,090.3/sq mi.