| State: | VA |
| Type: | VA |
| Route: | 84 |
| Alternate Name: | Mill Gap Road |
| Length Mi: | 14.94 |
| Length Round: | 2 |
| Map: | VA 84 map.svg |
| Established: | 1940 |
| Direction A: | West |
| Direction B: | East |
| Terminus A: | near Mill Gap |
| Terminus B: | at Vanderpool |
| Counties: | Highland |
| Previous Type: | VA |
| Previous Route: | 83 |
| Next Type: | I |
| Next Route: | 85 |
State Route 84 (SR 84) is a primary state highway in the U.S. state of Virginia. Known as Mill Gap Road, the state highway runs 14.94miles from the West Virginia state line near Mill Gap, where the highway continues west as West Virginia Route 84 (WV 84), east to U.S. Route 220 (US 220) at Vanderpool.
SR 84 begins at the top of Allegheny Mountain, which coincides with the Virginia - West Virginia state line and the Eastern Continental Divide. The highway continues west as WV 84, which descends the west side of the mountain to its terminus at WV 92 in Frost. The state highway passes through a pair of hairpin turns as it descends to Townsend Draft. At the draft's mouth at Back Creek, SR 84 turns north and follows Back Creek to Mill Gap, where the highway turns east and follows East Back Creek through its water gap between Little Mountain and Lantz Mountain. The state highway turns north and follows the valley through the hamlet of Mill Gap to Meadowdale. There, SR 84 turns east and follows the Jackson River through Vanderpool Gap between Monterey Mountain and Back Creek Mountain to its eastern terminus at US 220 (Jackson River Road) in the hamlet of Vanderpool south of the Highland County seat of Monterey.
Until 1933, SR 84 was part of State Route 39. It became State Route 271 in the 1933 renumbering, and in the 1940 renumbering it was renumbered State Route 84 to match West Virginia Route 84.
Although SR 39 was defined (as SR 9) in 1918,[1] its location west of Monterey was not finalized to follow the present SR 84 until 1923.