| State: | MT |
| Type: | MT |
| Route: | 84 |
| Map Custom: | yes |
| Map Notes: | MT 84 highlighted in red |
| Length Mi: | 28.904 |
| Direction A: | West |
| Terminus A: | in Norris |
| Direction B: | East |
| Terminus B: | near Four Corners |
| Counties: | Gallatin, Madison |
| Previous Type: | MT |
| Previous Route: | 83 |
| Next Type: | MT |
| Next Route: | 85 |
Highway 84 (MT 84) is a 28.904-longNaN-long east - west state highway in the U.S. State of Montana. MT 84's western terminus is at U.S. Route 287 (US 287) in the small community of Norris and the eastern terminus is at US 191 and MT 85 at Four Corners. The highway's eastern terminus, about 7miles west of Bozeman, is a location known locally as "Four Corners." From Four Corners, US 191 runs east to Bozeman, and south to West Yellowstone; Highway 84 travels west to Norris; and Montana Highway 85 runs north to Belgrade.
Before receiving its current designation, Highway 84 was designated as Montana Secondary Highway 289.