The Newburgh Conspiracy was an apparent planned military coup by the Continental Army in March 1783, at the end of the American Revolutionary War. The conspiracy may have been instigated by members in the Congress of the Confederation, who circulated an anonymous letter in the army camp at Newburgh, New York, on March 10, 1783. Soldiers were unhappy that they had not been paid for some time and that pensions that had been promised remained unfunded. The letter suggested that they should take unspecified action against Congress to resolve the issue. The letter was said to have been written by Major John Armstrong, aide to General Horatio Gates, although the authorship and underlying ideas are subjects of historical debate.

Commander-in-Chief George Washington stopped any serious talk of rebellion when he made an emotional address to his officers asking them to support the supremacy of Congress. Not long afterward, Congress approved a compromise agreement that it had previously rejected: it funded some of the pay arrears, and granted soldiers five years of full pay instead of a lifetime pension of half pay.

The motivations of numerous actors in these events are unclear. Some historians allege that serious consideration was given within the army to some sort of coup d'tat, while others dispute the notion. The exact motivations of congressmen involved in communications with army officers implicated in the events are similarly debated.

Newburgh is a city in the U.S. state of New York, within Orange County. With an estimated 2019 population of 28,177, it is a principal city of the Poughkeepsie–Newburgh–Middletown metropolitan area. Located 60 miles (97 km) north of New York City, and 90 miles (140 km) south of Albany on the Hudson River within the Hudson Valley Area, the city of Newburgh is located near Stewart International Airport, one of the primary airports for Downstate New York.

The Newburgh area was first settled in the early 18th century by the Germans and British. During the American Revolution, Newburgh served as the headquarters of the Continental Army. Prior to its chartering in 1865, the city of Newburgh was part of the town of Newburgh; the town now borders the city to the north and west. East of the city is the Hudson River; the city of Beacon is across the river and it is connected to Newburgh via the Newburgh–Beacon Bridge. The entire southern boundary of the city is with the town of New Windsor. Most of this boundary is formed by Quassaick Creek. In May 2016, the city requested help for its PFOS contaminated water supply under Superfund.Newburgh is the location of numerous preserved landmarks, including Washington's Headquarters, the David Crawford House, New York State Armory, the Dutch Reformed Church, and Newburgh Colored Burial Ground. George Washington and Franklin Delano Roosevelt had ties to the city; Ulysses S. Grant, Robert Kennedy, and Theodore Roosevelt also visited, the latter delivering a famous speech at a nearby shipyard. The city served as a planning ground for the Gothic Revival architectural movement in America, headed by native Andrew Jackson Downing with English architects Calvert Vaux and Frederick Clarke Withers.

Mount Saint Mary College is a private liberal arts college stimulating the city's population and economy. Major corporations with significant operations in the city of Newburgh are Stop & Shop, M&T Bank, Chase Bank, Verizon Communications, Charter Communications, Dunkin', McDonald's, Metro by T-Mobile, Boost Mobile, and Marshalls.