Black Oak is a town in Craighead County, Arkansas, United States.

According to the United States Census Bureau, the town has a total area of 0.4 square miles (1.0 km2), all land.

Ecologically, Black Oak is located within the St. Francis Lowlands ecoregion within the larger Mississippi Alluvial Plain.

The St. Francis Lowlands are a flat region mostly covered with row crop agriculture today, though also containing sand blows and sunken lands remaining from the 1811–12 New Madrid earthquakes.

[4] The St. Francis Sunken Lands Wildlife Management Area, which preserves some of the bottomland hardwood forest typical of this ecoregion prior to development for row agriculture lies just west of Black Oak along the St. Francis River.

There are two other, smaller, communities in Arkansas named Black Oak, one of which is in Washington County, approximately 8 miles (13 km) southeast of Fayetteville.