Vermont ( ) is a state in the New England region of the Northeastern United States. It borders Massachusetts to the south, New Hampshire to the east, New York to the west, and the Canadian province of Quebec to the north. As of the 2020 U.S. census, the state had a population of 643,503, ranking it the second least populated U.S. state. It is the nation's sixth smallest state in area. The state's capital of Montpelier is the least populous U.S. state capital. No other U.S. state has a most populous city with fewer residents than Burlington.

Native Americans have inhabited the area for about 12,000 years. The competitive tribes of the Algonquian-speaking Abenaki and Iroquoian-speaking Mohawk were active in the area at the time of European encounter. During the 17th century, French colonists claimed the territory as part of New France. Conflict arose when the Kingdom of Great Britain began to settle colonies to the south along the Atlantic coast; France was defeated in 1763 in the Seven Years' War, ceding its territory east of the Mississippi River to Britain. Thereafter, the nearby British Thirteen Colonies disputed the extent of the area called the New Hampshire Grants to the west of the Connecticut River, encompassing present-day Vermont. The provincial government of New York sold land grants to settlers in the region, which conflicted with earlier grants from the government of New Hampshire. The Green Mountain Boys militia protected the interests of the established New Hampshire land grant settlers. Ultimately, a group of settlers with New Hampshire land grant titles established the Vermont Republic in 1777 as an independent state during the American Revolutionary War. The Vermont Republic abolished slavery before any other U.S. state. It was admitted to the Union in 1791 as the 14th state.

The geography of the state is marked by the Green Mountains, which run north–south up the middle of the state, separating Lake Champlain and other valley terrain on the west from the Connecticut River Valley that defines much of its eastern border. A majority of its terrain is forested with hardwoods and conifers. The state has warm, humid summers and cold, snowy winters.

Vermont's economic activity of $40.6 billion in 2022 is ranked last on the list of U.S. states and territories by GDP, but 21st in GDP per capita. Known for its progressivism, the state was one of the first in the U.S. to recognize same-sex civil unions and marriage, has the highest proportion of renewable electricity generation at 99.9%, and is one of the least religious and least racially/ethnically diverse states. Dairy, forestry, maple syrup, and wine are important sectors in Vermont's agricultural economy. Vermont produces approximately 50% of the nation's maple syrup.