Finney County is a county located in the U.S. state of Kansas. Its county seat and most populous city is Garden City. As of the 2020 census, the county population was 38,470. The county was named for David Finney, the Lieutenant Governor of Kansas from 1881 to 1885. In 2020, 51.4 percent of the population in the county was Hispanic, one of a few counties in Kansas with a Hispanic majority population.

Finney County was established in 1883 and named after Lt. Gov. John W. Finney. The first white settlers arrived in 1878, settling along the Arkansas River and its tributaries.

What was to become Finney County began in March 1873 as Buffalo County and Sequoyah County(named after Sequoyah, the Cherokee Indian responsible for the development of the Cherokee alphabet. In 1881, the northern tier of townships was removed from Buffalo County and added to Lane County; the remainder was made part of newly-created Gray County, and later was taken to form part of Finney County. The two counties were merged in 1883 and renamed Finney County, in honor of then Lieutenant Governor David Wesley Finney. The county grew to the current shape after Garfield County was annexed to it in 1893 following a Supreme Court decision finding that Garfield County was less than one section/square mile short of the constitutionally defined minimum size of 432 square miles. The northeastern block, separate from the otherwise rectangular area, represents what at one time was Garfield County, which is now occupied partially by the Garfield Township. This combination of three separate counties makes Finney County the second-largest county in Kansas (after Butler County), comprising just over three times the constitutional minimum.

The town of Garden City was founded in 1879 by the cattle firm of Jones and Plummer, who established it as a shipping point for Texas cattle being driven along the Jones & Plummer Trail to Dodge City. Garden City grew rapidly as a railroad hub when the Atchison, Topeka & Santa Fe and Chicago, Rock Island & Pacific railroads arrived in 1888.

As described in Blackmar's Cyclopedia, Garden City "was a typical frontier town, with its gambling houses, dance halls and other adjuncts of border civilization" in its early years, but it quickly transformed into an agricultural center for southwestern Kansas.

Other early settlements such as Holcomb, Kalvesta, and Pierceville sprang up in the 1880s as Finney County became a prosperous region for wheat farming and cattle ranching. The county population boomed from just 537 in 1880 to over 5,000 by 1890 as homesteaders poured in.

In 1893, the former Garfield County was annexed into Finney County and organized as Garfield Township. Garfield County had originally been established in 1887 from parts of Finney County and other surrounding counties, but it struggled to maintain a viable tax base and population.

By 1910, Finney County had a population exceeding 10,000 as agriculture firmly took root in the region after its pioneering days on the frontier.