[3] Morgan County is part of the Knoxville, TN Combined Statistical Area.

It was named in honor of Daniel Morgan (1736–1802), an American Revolutionary War officer who commanded the troops that defeated the British at the Battle of Cowpens, and who later served as a U.S. congressman from Virginia.

At least seven people were killed in the Morgan County communities of Mossy Grove and Joyner.

The Crab Orchard Mountains comprise a large area of the county, which includes several designated wilderness areas, Frozen Head State Park, and Lone Mountain State Forest.

The Clear Fork, which forms part of Morgan's boundary with Fentress County, joins the New River in Scott County to the north to form the Big South Fork of the Cumberland River.

As of the 2020 United States census, there were 21,035 people, 7,625 households, and 5,659 families residing in the county.