Wellington, the county seat of Collingsworth County, is on U.S. Highway 83 in the south central part of the county. When Collingsworth County was organized in September 1890, Pearl City, two miles to the north of Wellington, was expected to be chosen county seat. However, land promoters from Childress County favored Wellington over Pearl City. They persuaded J. John Drew and Henry J. Nesper, manager and foreman, respectively, of the Rocking Chair Ranch in the northeastern part of the county, to urge the Rocking Chair cowboys to vote for Wellington. In addition, they offered the voters in the county five town lots each if they would choose Wellington. Wellington won the election by a vote of fifty-six to thirty-two. The legislature validated the election, despite the fact that Wellington had not received the two-thirds majority necessary for a county seat to be located more than five miles from the center of the county. The townsite of Wellington was the product of three promoters: E. T. O'Neil, John S. McConnell, and John W. Swearingen. They named it for the duke of Wellington because a relative of the earl of Aberdeen, who was one of the Rocking Chair's owners, had been with the duke at Waterloo. The first permanent building was a saloon moved by A. F. Swafford from Pearl City in 1891. A post office, with Mrs. Carrie Barton as postmistress, was granted at the same time. Mail was delivered by hack from Memphis. Two general merchandise stores were established. J. W. Koons taught the first school on the second floor of one of the stores. In 1893 a permanent county courthouse was completed. It was built of bricks baked at a kiln on Buck Creek, seven miles west of town near the homesite of the county's first resident, I. N. Bowers, who had settled there in 1876. By 1893 Wellington had five businesses, including O'Neil's two-story hotel, a church, and a separate schoolhouse. In 1898 Swafford's saloon was closed when the county voted dry.
After 1900 Wellington began to grow, and cotton began to rival cattle economically. The first gin was constructed in 1902, and by 1906 two banks had been chartered. In 1900 two newspapers, the Collingsworth Citizen and the Collingsworth Courier, began publication in Wellington, but both were short-lived. In 1902 W. A. Dunn and Wade Arnold began the Wellington Times. It sold out in 1911 to the Wellington Leader, which was started in 1909 by Thomas Durham. Business and population growth was further stimulated in 1910 when the Wichita Falls and Northwestern Railway reached the town. At that time the population was 600. In December 1910 Wellington was incorporated, and city officers were elected. W. H. Mims established the first electric power plant in 1912, and by 1916 a public water system had been installed. A second newspaper, the Collingsworth Standard, was begun by Aubrey Dobbs in 1924. In 1931 a larger county courthouse was built, and the Fort Worth and Denver Northern Railway reached the town. By 1934 Wellington had paved streets, a sewage system, natural gas, four churches, a hospital, many gins, a cotton compress, an ice plant, a creamery, three banks, five produce houses, and a population of 3,570. Since World War II Wellington has continued as a ranching and farming center, with several gins and grain elevators. Located there are manufacturers of mattresses, concrete, and railroad spikes. By 1970 the town had a modern high school, a new hospital and clinic, a public park, a golf course, a county library, a county historical museum, and ninety businesses. The population was 3,137 in 1960, 2,884 in 1970, and 3,043 in 1980 (then two-thirds of the county's residents). In 1990 the population was 2,546 and, in 2000 it was 2,275. Marian Airport is located just east of town.