Daniel Ogden Shays (August 1747 – September 29, 1825) was an American soldier, revolutionary and farmer famous for allegedly leading Shays' Rebellion, a populist uprising against controversial debt collection and tax policies that took place in Massachusetts between 1786 and 1787. The actual role played by Shays in the rebellion is disputed by scholars.

Daniel Ogden Shays was born in Hopkinton, Massachusetts, sometime between April and August 1747 to Irish immigrants Patrick Shays and Margaret Dempsey. Daniel was the second of seven siblings; his siblings were Margaret, James, Roger, Phebe, Mary, and Polly. He spent his early years as a landless farm laborer. In 1772, he married Abigail Gilbert, and they settled in Shutesbury, Massachusetts, where he owned a sixty-eight acre farm and they had six children.

Shays joined the militia immediately prior to the American Revolution and attained the rank of sergeant in the regiment commanded by Benjamin Ruggles Woodbridge. The Battles of Lexington and Concord took place on April 19, 1775, and the next day Shays's unit was mobilized and marched to Boston. His company took part in the Boston campaign and Siege of Boston, and Shays fought at the Battle of Bunker Hill. Shortly after Bunker Hill, Shays was commissioned as a second lieutenant in recognition of the bravery and skill he demonstrated during the fighting. In late 1776, Shays joined Varnum's Regiment of the Continental Army, with which he served during fighting in New York and New Jersey. After performing temporary recruiting duty in Massachusetts during late 1776, on January 1, 1777, Shays was promoted to captain as commander of a company in the 5th Massachusetts Regiment. During 1777, Shays took part in several engagements in upstate New York, including the Battles of Saratoga.

After Saratoga, Shays continued to serve with the Continental Army in upstate New York. As commander of a company in the Corps of Light Infantry, which was commanded by Anthony Wayne, Shays took part in the July 1779 Battle of Stony Point. He subsequently served as commander of a company under the Marquis de Lafayette, which patrolled farmland on the New Jersey side of the Hudson River to prevent British troops from foraging. In 1780, Lafayette presented several officers, including Shays, with ornamental swords in honor of their military service. Shays sold his for cash to help pay off debts; he argued that there was nothing wrong with his action, because he already owned a sword, but his decision to sell his was frowned upon by his peers. After British officer John André was captured while collaborating with Continental officer Benedict Arnold's plot to surrender West Point to the British, Shays was assigned as one of the captains of the guard who oversaw André's imprisonment, a task for which Continental Army commander-in-chief George Washington personally selected him. Shays was present when André was executed on October 2, 1780, and was probably the officer who escorted him to the gallows. Shays resigned soon afterwards, and was discharged from the army on October 14, 1780.

Upon returning home, Shays was summoned to court for unpaid debts, which he could not pay because he had not been paid in full for his military service. Shays was alarmed to discover that many of his fellow veterans and farmers were in the same financial situation. At commoners' meetings veterans asserted that they were treated unfairly upon release, and that businessmen were trying to squeeze money out of smallholders in order to pay their own debts to European war investors. Many Massachusetts rural communities first tried to petition the legislature in Boston, but the legislature did not respond substantively to those petitions.

The petitions and proposals often included a request to issue paper currency. Such inflationary issues would depreciate the currency, making it possible to meet obligations made at high values with lower-valued paper. Merchants, among them James Bowdoin, were opposed to these proposals because they were generally lenders who stood to lose. The proposals were repeatedly rejected. Governor John Hancock, accused by some of anticipating trouble, abruptly resigned in early 1785. When Bowdoin (a loser to Hancock in earlier elections) was elected governor that year, matters became more severe. Bowdoin stepped up civil actions to collect back taxes, and the legislature exacerbated the situation by levying an additional property tax to raise funds for the state's portion of foreign debt payments. Even comparatively conservative commentators like John Adams observed that these levies were "heavier than the People could bear".

Protests in rural Massachusetts turned into direct action in August 1786 after the state legislature adjourned without considering the many petitions that had been sent to Boston. On August 29, a well-organized force of protestors, Shays among them, marched on Northampton and successfully prevented the county court from sitting. The leaders of this and later forces proclaimed that they were seeking relief from the burdensome judicial processes that were depriving the people of their land and possessions. They called themselves Regulators, a reference to the Regulator movement of North Carolina that sought to reform corrupt practices in the late 1760s. On September 2, Governor Bowdoin issued a proclamation denouncing such mob action, but took no military measures in response beyond planning militia response to future actions.

When the court in Worcester was shut-down by similar action on September 5, the county militia (composed mainly of men sympathetic to the protestors) refused to turn out, much to Bowdoin's amazement.