Lavaca is a city located in the U.S. state of Arkansas. It is within Sebastian County included in the Fort Smith, Arkansas-Oklahoma Metropolitan Statistical Area. It has a total area of 2.19 square miles at 35°20′12″N 94°10′36″W. The elevation is 423 feet above sea level. As of the 2010 census data, it had a total population of 2,289. The population density was 1,098.90/sq mi. Estimated per capita income in 2015 was $21,671. It is using Zip code 72941.