Waterville is a city in Kennebec County, Maine, United States, on the west bank of the Kennebec River. The city is home to Colby College and Thomas College. As of the 2010 census the population was 15,722, and in 2019 the estimated population was 16,558. Along with Augusta, Waterville is one of the principal cities of the Augusta-Waterville, ME Micropolitan Statistical Area.