State Route 474 (SR 474, known as Merchants Greene Boulevard) was a 1.4-mile-long (2.3 km) five-lane state highway in Hamblen County in the eastern portion of the U.S. state of Tennessee.

It was decommissioned and designated as part of SR 66 following an extension project by TDOT in November 2020.

Dewitt Clinton Senter Highway) at a traffic signal southwest of Morristown.

The route then proceeds northwest through rural areas of Morristown.

It crosses over a Norfolk Southern Railway line then it continued to the northwest and meets its northern terminus, an intersection with US 11E/SR 34 (West Andrew Johnson Highway) in the western part of Morristown.