Essex County is a county located in the northeastern part of the U.S. state of Vermont. As of the 2020 census, the population was 5,920, making it the least-populous county in both Vermont and New England. Its shire town is the municipality of Guildhall. The county was created in 1792 and organized in 1800. Bordered by the Connecticut River next to New Hampshire, Essex County is south of the Canadian province of Quebec. It is the county with the lowest household-income in Vermont.

The Northeast Kingdom is the northeast corner of the U.S. state of Vermont, approximately comprising Essex, Orleans, and Caledonia counties and with a population of 64,764 at the 2010 census. The term "Northeast Kingdom" is attributed to George D. Aiken, former Governor of Vermont and a U.S. senator, who first used the term in a 1949 speech.