Mercer is a community located in the U.S. state of Maine. It is within Somerset County which derived its name from Revolutionary War hero Brigadier General Hugh Mercer. It has a total area of 27.36 square miles at 44°40′11″N 69°53′26″W. The elevation is 479 feet above sea level. As of the 2010 census data, it had a total population of 664. The population density was 24.9/sq mi. Estimated per capita income in 2016 was $26,661. Recent job growth is negatively decreased by 2.28 percent. The average travel time is 17 minutes.