Lavaca (/ləˈvɑːkə/ ⓘ lə-VAH-kə) is a city in Sebastian County, Arkansas, United States.

It is part of the Fort Smith, Arkansas-Oklahoma Metropolitan Statistical Area.

According to the United States Census Bureau, the city has a total area of 2.2 square miles (5.7 km2), all land.

As of the 2020 United States census, there were 2,450 people, 951 households, and 693 families residing in the city.

18.7% of all households were made up of individuals, and 6.1% had someone living alone who was 65 years of age or older.