Fairfield Bay is a city in Cleburne and Van Buren counties in the northern part of the U.S. state of Arkansas. The population was 2,108 at the 2020 census. The population in its portion in Van Buren County, which accounts for the bulk of the city limits, made the city the most populous in Van Buren County as of the 2000 census, but with a slight decline in population, lost the distinction to Clinton as of 2010.