Kinney County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 3,129. Its county seat is Brackettville. The county was created in 1850 and later organized in 1874. It is named for Henry Lawrence Kinney, an early settler.

Kinney County's self-proclaimed biggest issue since the 2010s is undocumented immigration from Mexico through the county. The county claims it does not have the resources to deal with the large number of migrants, and in 2021 proclaimed a state of emergency.

The first inhabitants were 6,000–10,000 years ago and later came to include Lipan Apache, Mescalero Apache, Coahuiltecan, Jumanos, Tamaulipans, Tonkawa, and Comanches. These tribes settled in rock shelters in the river and creek valleys, leaving behind artifacts and caches of seeds, implements, burial sites, and petroglyphs.

Most of the Indians that raided the county after the civil war were the Kickapoo, Seminole, and Lipan Apache. These Indians sometimes worked with Mexicans to raid the area.

The last Native American raid in the county was likely in April of 1881 when Lipan Apaches were attacked by U.S soldiers after the raid on the Frio Canyon in Real County.

Saltillo Alcalde Fernando de Azcué passed through the southeast corner of the county in 1665 on an expedition, becoming the first European to cross the Rio Grande. Franciscan Brother Manuel de la Cruz explored the county in 1674. In 1675, Fernando del Bosque traversed the area on an expedition up the Rio Grande from the city of Nuestra Sra. de Guadalupe. He was accompanied by Franciscan friars Juan Larios and Dionisio de San Buenaventura. Alonso De León in 1688 discovered French explorer and La Salle expedition deserter Jean Henri in a somewhat confused state of mind, among the Coahuiltecan Indians near the site of present Brackettville, generally believed to be at Anacacho Mountain. During the late 18th century, several Franciscans established a settlement on Las Moras Creek near the center of the county. In 1834, while the area was still under Mexican control, English land speculators John Charles Beales and James Grant attempted to establish an English-speaking colony called Dolores at the site. Streets were laid off and 59 colonists were brought in, but the project was abandoned.

The state legislature formed Kinney County from Bexar County in 1850, five years after Texas statehood, and named it for Henry Lawrence Kinney. The United States Army established Fort Clark in June 1852 on Las Moras Creek, and named it after John B. Clark, who had died in the Mexican War. Brackettville was founded in 1852 originally as the town of Brackett and named for Oscar B. Brackett, who came to set up a stage stop and opened the town's first dry-goods store. Brackett became a stop on a stage line from San Antonio to El Paso, but the settlement grew very slowly because of continuous Indian attacks. The town received its first post office in 1875. On February 18, 1861, on orders from United States Army General David E. Twiggs, Fort Clark was surrendered to the Texas Commission. Twiggs was dismissed by the United States for the act, and subsequently joined the Confederacy. The fort was evacuated by federal troops on March 19 and occupied by Confederate troops under the command of Confederate Colonel John R. Baylor. It remained in the hands of the Confederates until the end of the war, but was not garrisoned. In December 1866, it was reestablished as a federal fort.

In early 1872, a number of Black Seminoles living along the border were organized into a company of scouts and brought to Fort Clark. Others joined them, and by the mid-1870s, they numbered some 400 to 500. For the next quarter century, they lived on a reservation along Las Moras Creek. In 1914, the Black Seminoles were removed from the Fort Clark reservation, but some of their descendants still live in the county. The Seminole Indian Scouts cemetery was founded on Fort Clark in 1872.