Columbia County is a county in the U.S. state of New York. At the 2020 census, the population was 61,570. The county seat is Hudson. The name comes from the Latin feminine form of the surname of Christopher Columbus, which was at the time of the formation of the county a popular proposal for the name of the United States. The county is part of the Capital District region of the state.

At the arrival of European colonists the area was inhabited by the indigenous Mohican Indians. To the west of the river were the Mohawk and other four tribes of the Iroquois Confederacy, extending past what is now the border of New York state. The first known European exploration of Columbia County was in 1609, when Henry Hudson, an English explorer sailing for the Dutch, ventured up the Hudson River. An accident to his craft forced him to stop at what is now known as Columbia County and there search for food and supplies. In 1612, the Dutch established trading posts and minor settlements, building New Amsterdam (now New York City) and Fort Orange (now Albany). Fort Orange became a center of the fur trade with the Mohawk people. Traders stopped at points along the Hudson River on their travels between New Amsterdam and Fort Orange; small settlements arose along the river to supply the traders' ships.

Dutch colonists bought land [from whom?] near Claverack in 1649 and 1667. As more Dutch arrived, the region slowly developed. In 1664, the English took over New Netherland and renamed it the "Province of New York"; they also renamed Fort Orange "Albany".

In the late 17th century, Robert Livingston, a Scots immigrant by way of Rotterdam, built on his connections as Indian agent in the colony and purchased two large tracts from the Native Americans. He gained much larger grants from the provincial government, for a total of 160,240 acres. He was made lord of Livingston Manor by the Crown, with all its perquisites, and developed the property with tenant farmers. In 1710, he sold 6,000 acres of his property to Queen Anne of Great Britain for use as work camps and for the resettlement of Palatine German refugees. The Crown had supported their passage to New York, and they were to pay off the cost by indentured labor. Some 1,200 Palatine Germans were brought to Livingston Manor (now Germantown). New York's Governor Hunter had also helped with these arrangements: the workers were to make naval stores (e.g., pitch, resin, and turpentine) from the pine trees in the Catskill Mountains.

They were promised land for resettlement after completing their terms of indenture. They were refugees from years of religious fighting along the border with France, as well as crop failures from a severe winter. Work camps were established on both sides of the Hudson River. The Germans quickly established Protestant churches at the heart of their community, which recorded their weddings, births and deaths, among the first vital records kept in the colony.

After many years, some of the colonists were granted land in the frontier of the central Mohawk Valley west of present-day Little Falls in the 100 lots of the Burnetsfield Patent; in the Schoharie Valley, and other areas, such as Palatine Bridge along the Mohawk River west of Schenectady. They were buffer communities between the British settlements and the Iroquois and French (the latter located mostly in Canada.)

Columbia County was formed in 1786 after the American Revolutionary War from portions of Albany County, once a vast area until new communities were developed and jurisdictions were organized. In 1799, the southern boundary of Columbia County was moved southward to include that portion of Livingston Manor located in Dutchess County.

In the nineteenth century, the Vermont Central Railway was constructed to the area. It provided transportation north towards Rutland and Burlington, Vermont, and south towards the major junction town of Chatham, New York, for travel to points west, south and east.