Texarkana is a city in the U.S. state of Arkansas and the county seat of Miller County, on the southwest border of the state. As of the 2020 census, it had a population of 29,387. It is the twin city of Texarkana, Texas, located just across the state line. The city was founded at a railroad intersection on December 8, 1873, and was incorporated in Arkansas on August 10, 1880. Texarkana and its Texas counterpart are the principal cities of the Texarkana metropolitan area, which in 2021 was ranked 289th in the United States with a population of 147,174, according to the United States Census Bureau.

Within the Ark-La-Tex subregion of southwest Arkansas, Texarkana is located in the Piney Woods, an oak–hickory forest that dominates the flat Gulf Coastal Plain. Texarkana's economy is based on agriculture. The city has long been a trading center, first located at the intersection of major railroads serving Texas, Arkansas and north into Missouri. Since then three major Interstate highways constructed crossroads here: Interstate 30 (I-30), I-49, and the future I-69. The Red River Army Depot is the largest single employer in the city.

The Texarkana Arkansas School District is the largest public school district on the Arkansas side. The city has a branch campus of the University of Arkansas Hope-Texarkana (UAHT). Texarkana College is located on the Texas side.

Miller County was formed in 1820 in the Arkansas Territory; it was named in honor of James Miller, Arkansas' first territorial governor and a general during the War of 1812. Much of its eastern border is formed by the Red River. At the time, there was considerable uncertainty among Americans as to the location of the boundary between the county (and the United States) and national territory of Mexico, which then included Texas.

Consequently, settlers believed that Arkansas levied and collected taxes on land that eventually might be held by Mexico. Moreover, many who resented what they considered Mexican oppression of European-American Texans were openly declaring allegiance to the Texans.

After the Texas Republic gained independence from Mexico, regional unrest increased. In 1838, Governor James Conway proposed that the "easiest and most effective remedy is the abolition of Miller County to an area which is more patriotic." Miller County was dissolved and its land was made part of Lafayette County, Arkansas.

In 1873 town lots were sold in Texarkana, Arkansas, at the intersection of two railroads, which stimulated its growth as a trading center. In this area and time period, railroads had replaced rivers as the preferred method of transportation and shipping, and new towns were sited for best advantage via the railroad. The next year (1874), Texarkana, Texas, was founded on the rail line on June 12 across the state border.

That same year, the Arkansas legislature re-established Miller County. Efforts of the young town in Arkansas to be incorporated were not realized until October 17, 1880, nearly seven years after Texarkana, Texas, was formed. Both Texarkana cities generally recognize December 8, 1873, as the date of organization.