Harriman is a city located primarily in Roane County, Tennessee, with a small extension into Morgan County. The population of Harriman was 6,350 at the time of the 2010 census.
Harriman is included in the Knoxville, Tennessee Metropolitan Statistical Area.
Harriman is located at 35°55′43″N 84°33′21″W (35.928585, -84.555700). The city is situated along the physiographic boundary between the Tennessee Valley region and the Cumberland Plateau region, with the Plateau—namely its Walden Ridge escarpment—rising several hundred feet above the city to the west. The Emory River enters the Tennessee Valley just west of Harriman at a pass known as Emory Gap, and forms an oxbow bend that surrounds the original section of Harriman.
U.S. Route 27, known as Roane Street in Harriman, runs north-to-south through the city along the base of Walden Ridge. Interstate 40 runs east-to-west through the city's southern section. Harriman's southwestern boundary, which it shares with Rockwood, is located along US-27 about a half-mile south of the road's intersection with I-40. The city's southeastern boundary runs along Pine Ridge, which overlooks the Kingston Fossil Plant. Harriman's northern boundary is near US-27's split with State Highway 61.