Effingham County is a county located in the southeastern part of the U.S. state of Georgia. As of the 2020 census, the population was 64,769. The seat is Springfield. Effingham County is included in the Savannah metropolitan area. In 2008, Effingham County was ranked as the sixth-fastest-growing midsize county in the nation from 2000 to 2007 by the U.S. Census Bureau. The county had a 35.1% growth rate over that period.