The Hudson River School was an art movement in the United States in the middle of the 19th century. It was led by a group of landscape painters whose style was influenced by Romanticism. Most of the time, the paintings show the Catskill, Adirondack, White Mountains, and the Hudson River Valley. The second generation of artists from the school drew on more places in New England, the Maritimes, the American West, and South America in their work.

People think that art critic Clarence Cook of the New York Tribune or landscape painter Homer Dodge Martin came up with the name "Hudson River School." It was misused because the style was no longer popular after the Plein-air Barbizon School became popular with American patrons and collectors.

The paintings of the Hudson River School show three things about America in the 1800s: discovery, exploration, and settlement. They also offer the American landscape as a peaceful place where people and nature live together. Hudson River School landscapes show character in a realistic, detailed, and sometimes idealized way. They often show friendly farming next to the last bits of wilderness in the Hudson Valley, disappearing just as it was starting to be appreciated for its ruggedness and beauty. In general, Hudson River School artists thought that the American landscape, made up of nature, was a reflection of God. However, they had different levels of religious faith. They were influenced by artists like Claude Lorrain, John Constable, and J. M. W. Turner from Europe. Some artists were part of the Düsseldorf school of painting, and others were taught by Paul Weber, who was also German.

Hudson River School art had had short times when it was trendy again. After World War I, people became more interested in school, probably because of nationalist ideas. The number of people interested in the movement went down until the 1960s, and the regrowth of the Hudson Valley has made more people interested in it. Olana State Historic Site in Hudson, New York, the Thomas Cole National Historic Site in the town of Catskill, the Newington-Cropsey Foundation's historic house museum, art gallery, and research library in Hastings-on-Hudson, New York, and the John D. Barrow Art Gallery in the village of Skaneateles, New York, are all places that are dedicated to the Hudson River School.