U.S. Route 70 (US 70) enters the state of Tennessee from Arkansas via the Memphis & Arkansas Bridge in Memphis, and runs west to east across 21 counties in all three Grand Divisions of Tennessee, with a total length of 478.48 miles (770.04 km), to end at the North Carolina state line in eastern Cocke County.

After that, it then continues eastward through Waverly, Dickson, and Kingston Springs before making entry into Nashville.

After US 431 and US 70S splits from the main route on Broadway, US 70 progresses eastward, roughly paralleling the Cumberland River, ducking under the western split of I-40 and I-24, and continuing to an interchange with SR 155 (Briley Parkway) east of downtown, and then Old Hickory Boulevard in Hermitage.

Before crossing the Tennessee River for a second time, US 25W begins to follow US 70 (SR 9) from the east side of Knoxville until it merges with US 25E at Newport.

State Route 26 (SR 26) runs concurrently with US 70 for its entire existence through Wilson, De Kalb and White Counties in Middle Tennessee.

The 59.25 miles (95.35 km) long state highway runs from Lebanon downtown Sparta.