Kennebec County is a county located in the U.S. state of Maine. As of the 2010 census, the population was 122,151. Its county seat is Augusta, the state capital. The county was established on 20 February 1799 from portions of Cumberland and Lincoln Counties. The name Kennebec comes from the Eastern Abenaki /kínipekʷ/, meaning "large body of still water, large bay".