Saint Johnsbury
- Country: United States
- State: Vermont
- Population: 6,193 (2010)
- Latitude: 44° 25.2' N (44.41922°)
- Longitude: 72° 0.9' W (-72.01509°)
- Elevation: 182 m/597 ft. above sea level
- Time zone: America/New_York (UTC -05:00); DST observed (UTC -04:00)
- Alternate names: Saint Johnsbury CDP, Saint Johnsbury Plain, St. Johnsbury, St. Johnsbury CDP, St. Johnsbury Plain