The Battle of Arkansas Post, also known as Battle of Fort Hindman, was fought from January 9 to 11, 1863, near the mouth of the Arkansas River at Arkansas Post, Arkansas, as part of the Vicksburg Campaign of the American Civil War. Confederate forces had constructed a fort known as Fort Hindman near Arkansas Post in late 1862. In December of that year, a Union force under the command of Major-General William T. Sherman left for an expedition against Vicksburg, without Major-General John A. McClernand because neither Major-Generals Henry Halleck nor Ulysses S. Grant trusted McClernand. After Sherman's force was repulsed at Chickasaw Bayou, McClernand arrived and took command from Sherman in January 1863.

The Arkansas Post, formally the Arkansas Post National Memorial, was the first European settlement in the Mississippi Alluvial Plain and present-day U.S. state of Arkansas. In 1686, Henri de Tonti established it on behalf of Louis XIV of France for the purpose of trading with the Quapaw Nation. The French, Spanish, and Americans, who acquired the territory in 1803 with the Louisiana Purchase, considered the site of strategic value. It was the capital of Arkansas from 1819 until 1821 when the territorial government relocated to Little Rock.