Madill is a city in and the county seat of Marshall County, Oklahoma, set in the south-central part of the state along the Red River border with Texas. It sits just north of Lake Texoma, one of the region's largest reservoirs, and functions as the governmental and commercial hub for a county that is small in population but rich in lake-country recreation. The city reported 3,914 residents at the 2020 census. Madill's history is tied to the railroad and the Chickasaw Nation. Marshall County was created at Oklahoma statehood in 1907 from the former Pickens County of the Chickasaw Nation, and Madill was named for George Alexander Madill, an attorney for the St. Louis–San Francisco Railway. The coming of the railroad established the town as a shipping and trading point for the surrounding agricultural region, a role it has carried into the present as the county seat. The city's defining cultural event is the National Sand Bass Festival, held each June since 1963. The week-long celebration grew out of the spring spawning runs of sand bass in Lake Texoma's tributaries and now includes fishing tournaments, live entertainment, a carnival, and food and craft vendors, drawing more than 15,000 visitors to a city of under 4,000. The festival anchors Madill's identity as the gateway to Lake Texoma. Beyond the lake, Madill is a working small town whose economy combines county government, education, agriculture, and tourism. Students attend Madill Public Schools, a compact three-campus district, and U.S. Highways 70 and 377 connect the city to Durant, Ardmore, and the broader region. For households seeking affordable small-town living with immediate access to one of the southern plains' premier reservoirs, Madill offers a distinctive combination of civic center and lake-country lifestyle.