Located just north of the center of Caledonia County in the Passumpsic River Valley, Lyndon was founded in 1780. Its land is uneven with several hills and valleys carved by the many tributaries of the Passumpsic. It is cornered on the southwest by Danville, west by Wheelock, north by Sutton and Burke, and east by Burke and Kirby. The town contains the villages of Lyndonville, Lyndon Center and Lyndon Corner.

Lyndon is known as the “Covered Bridge Capital of Vermont’s Northeast Kingdom.” The town is divided into meadow and upland which has been used effectively for agriculture. Its riverside location made it ideal for mills, factories and machinery. The Connecticut and Passumpsic Rivers Railroad ran through the center of town. Lyndon was founded in 1780 by Hon. Jonathan Arnold, Daniel Cahoon and Daniel Owen of Providence, R.I., an exploring committee of an association of about 50 enterprising citizens of that city to settle a colony in the new state of Vermont. Barnet, Peacham and Ryegate were the only chartered towns at the time. Standing on the summit of the high hill in Lyndon Corner, they mapped out their new town, which was a popular hunting ground for Native Americans. When the town was granted to Arnold and his associates, it was called Bestbury. The name was changed to Lyndon in honor of  Arnold's oldest son, Josias Lyndon Arnold, a native of Providence. He was a highly-educated lawyer and poet who settled in St. Johnsbury, but eventually decided backwoods life was not for him.

 Jonathan Arnold would go on to secure charters for Billymead (now called Sutton) and St. Johnsbury, where he settled and died in 1793. Lyndon was once famous for its cattle and livestock, especially horses which were held in the highest regard across the country. Native trees of white pine, spruce, hemlock, fir, cedar, sugar maple, beech, birch, elm, ash and tamarack were prominent. Daniel Cahoon cleared the first home site and built the first cabin, relying for survival on forests full of game and rivers teaming with trout. Cahoon would become the first town clerk, lister and selectmen. In 1792, the first property tax was enacted to help with the building of bridges and highways.

Over the next several decades the town grew significantly in population. In 1931, during Prohibition, a Boston newspaper referred to Lyndonville as a haven for “rum running” gangsters, due to its proximity to the Canadian border. The town is home to Lyndon State College, a four-year liberal arts school founded in 1911, originally to train teachers. Lyndon Center is the home of Lyndon Institute, an independent high school that offers programs in arts, sciences, technology, and athletics. The school was founded in 1867 and now has students from across the country and around the world.

These days Lyndonville is a bustling downtown village divided by Route 5, a well-traveled north-south corridor. Over the years, manufacturing, tourism, agriculture and retail have been staples of the economy. There is an industrial park located between Lyndonville and St. Johnsbury.