Tyler County lies in the northwestern region of West Virginia in the Ohio River Valley. It is bordered on the west by the Ohio River, - and Monroe County, Ohio - on the north by Wetzel County, on the east by Doddridge County, and on the southeast and south by Ritchie and Pleasants counties. Prior to the formation of the state of West Virginia on June 20th in 1863, Tyler County was a county in the state of Virginia.

Tyler County was formed from Ohio County on December 6, 1814. It was named for John Tyler who was the governor of Virginia from 1808 to 1811. Subsequently, the entirety of Wetzel (1846) and parts of Doddridge (1845) and Pleasants (1851) counties were formed from the territory of Tyler.

The first county seat was Sistersville. The courts met at the homes of various individuals. In 1816 the county seat was moved to Middlebourne. In 1818 the first jail was built in Middlebourne, but the courts continued to be held in private homes. In 1822 the first courthouse was built on part of the the site where the present one stands. It was torn down and a new courthouse constructed in 1854. That building was completely renovated in 1922, resulting in the courthouse that is now in use.

Tyler County has an area of 261 square miles and the population as of 2000 was 9,592. The largest inland stream is Middle Island Creek. This stream is 77 miles in length and transverses Doddridge, Tyler and Pleasants Counties, where it enters the Ohio River. A unique feature occurs in Tyler County, where the creek flows in a 7 mile bend that causes it to return to within 100 feet of where the bend starts. This effectively forms a peninsula and the area is known as "The Jug" because the shape of the creek resembles a jug handle.

The main highways are State Routes 2, 18, 23, and 74. Incorporated towns include Middlebourne, Sistersville, Paden City, and Friendly. There are numerous unincorporated communities, some of which are: Adonis, Alma, Alvy, Bearsville, Blue, Falls Mills, Frew, Josephs Mills, Kidwell, Lima, Little, Mountain, Pursley, Shiloh, Shirley, Tyler City, Wick, and Wilbur.