Fayette County is a county located in the U.S. state of Tennessee. As of the 2020 census, the population was 41,990. Its county seat is Somerville. The county was named after the Marquis de la Fayette, French hero of the American Revolution. A part of the Memphis, TN-MS-AR Metropolitan Statistical Area, Fayette County is culturally alike to the Mississippi Delta and was a major area of cotton plantations dependent on slave labor in the nineteenth century.

Fayette County was established by Tennessee General Assembly in 1824 from the neighboring counties of Shelby and Hardeman. The same year, Somerville was selected as its county seat. The first churches in the county were the First Presbyterian Church in Somerville, established in 1829, and Immanuel Parish, established in 1832.

Herb Parsons 1908–1959) of Somerville, Tennessee, was Winchester's "Showman Shooter" for 30 years.

Following the emancipation of slaves on plantations, many of Fayette County's African-American residents worked as sharecroppers. In the 1960s and 1970s, civil rights activists fought for school integration and voting rights; and created tent cities to house displaced tenant farmers who had tried to register to vote.

In recent years, Fayette County has been transitioning from a rural area to accommodate the suburban sprawl from Memphis.

According to the U.S. Census Bureau, the county has a total area of 706 square miles (1,830 km²), of which 705 square miles (1,830 km²) is land and 1.5 square miles (3.9 km²) (0.2%) is water. It is the third-largest county in Tennessee by area. The county is, roughly, the same size as Marshall County, Mississippi.

Since the four-lane expansion of Highway 64 in the early 1990s, western Fayette County has had a population explosion. Although the county seat is still in Somerville, the population of Oakland has far surpassed it because of the influx of people working in Shelby County and seeking more affordable housing.

Although Fayette County is growing on its western side, the county's economy is still based on agriculture. Historically it was a site of cotton plantations as part of the Mississippi Delta. Several of the county's largest farmers control the vast majority of the county's wealth. Some of these families have been farming for generations dating back to plantations before the Civil War. Others are younger farmers who have used their skill, business savvy, and work ethic to develop large farming operations.^{[citation needed]}