Burlington is the most populous city in the U.S. state of Vermont and the seat of Chittenden County. It is located 45 miles (72 km) south of the Canada–United States border and 95 miles (153 km) south of Montreal. As of the 2020 U.S. census, the population was 44,743. It is the least populous city in the 50 U.S. states to be the most populous city in its state. A regional college town, Burlington is home to the University of Vermont (UVM) and Champlain College. Vermont's largest hospital, the UVM Medical Center, is within the city limits. The City of Burlington owns Vermont's largest airport, the Patrick Leahy Burlington International Airport, located in neighboring South Burlington. In 2015, Burlington became the first city in the U.S. to run entirely on renewable energy.