Summers County, located in southeastern West Virginia, encompasses 367.6 square miles. Hinton is the county seat. Summers County was established on February 27, 1871, from segments of Fayette, Greenbrier, Mercer, and Monroe counties. The county was named after George W. Summers (1804-68), a noted jurist, legislator, and one of West Virginia's founders. At the time of its formation, the county was almost entirely rural and agricultural, but the newly arrived Chesapeake & Ohio Railway soon had a transforming effect.

Physiographically, Summers County is superimposed on folded Mississippian and Pennsylvanian rock strata, predominantly shales and sandstones. New River is the dominant stream, entering Summers County at the Virginia border and exiting below Sandstone Falls, the largest cataract on the New. Two major tributaries enter New River in Summers County, the Greenbrier and Bluestone rivers. During the mid-20th century, Bluestone Dam was constructed to control flooding on New River. This dam created Bluestone Lake, which has become a major recreational facility.

The climate is classified as continental, characterized by a wide seasonal temperature range and moderate amounts of precipitation. Summers County is heavily forested. The trees include various oaks, as well as hickory, tulip poplar, hemlock, maple, white pine, and many others. Some of the understory species are dogwood, laurel, sourwood, and rhododendron. Animals include black bear, white-tailed deer, squirrels, turkey, and many other species of birds, fish, mammals, reptiles, and amphibians.

Human habitation spans at least 10,000 years. The first inhabitants were Paleo-Indian people, and over time most Indian cultures that inhabited the eastern United States either lived in or traveled through the present county, as evidenced by their artifacts and by the interlacing trails that traversed the area.

The first European explorers probably arrived in 1671, when the Batts and Fallam expedition is believed to have reached present Summers County. Dr. Thomas Walker arrived in 1750. Walker's journal noted "plantations," early pioneer settlements, established on the Greenbrier River by the Greenbrier Company. In 1753, Andrew Culbertson settled on the floodplain of New River at Crump's Bottom, several miles upstream from present Hinton. These settlements were all erased during the French and Indian War in 1755. By about 1760, settlers had returned, but these new settlements were destroyed during Pontiac's Rebellion in 1763. By the Revolutionary War in the 1770s, Fort Culbertson had been built. Permanent settlements were established along the New, Greenbrier, and Bluestone. Settlement, and peaceful development continued into the early 19th century.

During the Civil War, most local residents supported the Confederacy. Most men fought in either the Army of Northern Virginia or Pickett's New River Regiment, while locally formed detachments participated with other Southern units. Thurmond's Rangers, Confederate partisan irregulars, drew men from the area. Military action in present Summers County was limited to skirmishes, some of which were the bloody culmination of preceding feuds between families. Bushwhackers were common.

Pack's Ferry, at the confluence of the Bluestone and New rivers, was an important river crossing on the James River & Kanawha Turnpike. Union forces held Pack's Ferry with entrenched artillery. Mercer Saltworks on Lick Creek was another military target, only 20 miles from the Virginia border in a territory thick with Confederate sympathizers. Union troops burned and destroyed the saltworks in August 1862, under the command of Col. Rutherford B. Hayes, who later became president. One of the last skirmishes of the war was fought on the lower Greenbrier River between irregulars who were unaware of Lee's recent surrender at Appomattox. A monument to the Confederacy was erected in 1914 in Hinton.

Soon after the war, the coming of the railroad brought big changes to southern West Virginia. The legendary John Henry helped build Great Bend Tunnel at Talcott, memorialized in the folk song as the Big Bend Tunnel. The Chesapeake & Ohio (C&O) was influential in establishing the county in 1871. Among local leaders who helped promote Summers County's formation was John Hinton. The C&O was completed through the New River Gorge in 1873, and the town of Hinton became a major railroad center. By 1900 Hinton was a boom town; in its heyday, a train stopped every 15 minutes in the Hinton yards. The New River coalfields kept the trains rolling and the economy of Hinton stable into the middle of the 20th century.

During the 1950s, a combination of factors led to the decline of the local economy. Coal mining technology changed, older mines played out, the local manufacture of coke was no longer viable, and—most importantly for Hinton—in 1954-55 the diesel locomotive replaced coal-fired steam power on the C&O. The railroad no longer required hundreds of workers for its Hinton maintenance operations. The city's population, which had stood at 6,654 in 1930 and 5,780 in 1950, was 2,266 in 2020. Summers County’s population peaked at 20,469 in 1930 and had fallen to 11,959 in 2020.

Summers County has diversified its economy and promoted tourism. All or parts of the Hinton National Historic District, New River Gorge National Park and Preserve, Pipestem Resort State Park, the Bluestone National Scenic River, Bluestone State Park, and Bluestone Lake are located within the county.

The new consolidated Summers County High School was opened in 1995. Between 2008 and 2012, the school's Lady Bobcats basketball team set a state record for boys or girls by winning 105 games in a row.

In 2023, Summers County's largest employers were the county school system, the state Division of Natural Resources, Appalachian Regional Healthcare, Summers Nursing and Rehabilitation Center, and Brayman Construction.