Sevier County as it is known today was formed on September 18, 1794 from part of neighboring Jefferson County, and has retained its original boundaries ever since. The county takes its name from John Sevier, governor of the failed state of Franklin and first governor of Tennessee, who played a prominent role during the tumultuous early years of settlement in the region.

Since its establishment in 1795, the county seat has been situated at Sevierville (also named for Sevier), the eighth-oldest city in Tennessee.

Prior to the late 1930s, Sevier County's population, economy, and society— which relied primarily on subsistence agriculture— held little significance vis-à-vis any other county in the rural South. However, with the creation of the Great Smoky Mountains National Park in the early 1930s, the destiny of Sevier County, within the bounds of which lies thirty percent of the total area of the national park, changed drastically. Today, rampant tourism supports the county's burgeoning economy which does not appear to be slowing any time in the near future.