St. Johnsbury is the shire town of Caledonia County, Vermont, United States. As of the 2020 census, the population was 7,364. St. Johnsbury is situated on the Passumpsic River and is located approximately six miles northwest of the Connecticut River and 48 miles south of the Canada–U.S. border. St. Johnsbury is the largest town by population in the Northeast Kingdom of Vermont and has long served as a commercial center for the region.