Major General Nathanael Greene (August 7, 1742 – June 19, 1786) was an American military officer and planter who served in the Continental Army during the Revolutionary War. He emerged from the war with a reputation as one of George Washington's most talented and dependable officers and is known for his successful command in the Southern theater of the conflict.

Born into a prosperous Quaker family in Warwick, Rhode Island, Greene became active in the colonial opposition to British revenue policies in the early 1770s and helped establish the Kentish Guards, a state militia unit. After the April 1775 Battles of Lexington and Concord, the legislature of Rhode Island established an army and appointed Greene to command it. Later in the year, Greene became a general in the newly established Continental Army. Greene served under George Washington in the Boston campaign, the New York and New Jersey campaign, and the Philadelphia campaign before being appointed quartermaster general of the Continental Army in 1778.

In October 1780, Washington appointed Greene as the commander of the Continental Army in the southern theater, where he was involved in several engagements, primarily in Virginia, Georgia, and South Carolina. After taking command, Greene engaged in a successful campaign of guerrilla warfare against a numerically superior British force led by Charles Cornwallis. He suffered a series of tactical defeats at Guilford Court House, Hobkirk's Hill, and Eutaw Springs, which nevertheless eroded British control over the American South.

Major fighting on land came to an end following the surrender of Cornwallis at the siege of Yorktown in October 1781, but Greene continued to serve in the Continental Army until late 1783. After the war, he settled down to a career as a plantation owner in Georgia, but his rice crops were mostly a failure. He died in 1786 at the Mulberry Grove Plantation in Chatham County, Georgia. Numerous locations in the United States are named for him.

Greene was born in 1742 on Forge Farm at Potowomut in the township of Warwick, Rhode Island, which was then part of the Colony of Rhode Island and Providence Plantations in British America. He was the second son of Mary Mott and Nathanael Greene Sr., a prosperous Quaker merchant and farmer. Greene was descended from John Greene and Samuel Gorton, both of whom were founding settlers of Warwick. Greene had two older half-brothers from his father's first marriage and was one of six children born to Nathanael and Mary. Due to religious beliefs, Greene's father discouraged book learning, as well as dancing and other activities. Nonetheless, Greene convinced his father to hire a tutor, and he studied mathematics, the classics, law, and various works of the Age of Enlightenment. At some point during his childhood, Greene gained a slight limp that would remain with him for the rest of his life.

In 1770, Greene moved to Coventry, Rhode Island, to take charge of the family-owned foundry, and he built a house in Coventry called Spell Hall. Later in the year, Greene and his brothers inherited the family business after their father's death. Greene began to assemble a large library that included military histories by authors like Julius Caesar, Frederick the Great, and Maurice de Saxe.

In July 1774, Greene married the nineteen-year-old Catharine Littlefield, a niece by marriage of his distant cousin, William Greene, an influential political leader in Rhode Island. The same year, one of Greene's younger brothers married a daughter of Samuel Ward, a prominent Rhode Island politician who became an important political ally until his death in 1776. Greene and Catherine's first child was born in 1776, and they had six more children between 1777 and 1786.

After the French and Indian War (1754–1763), the British parliament began imposing new policies designed to raise revenue from British America for a war which colonists had played a pivotal role in instigating. After British official William Dudington seized a vessel owned by Greene and his brothers, Greene filed an ultimately successful lawsuit against Dudington for damages. While the lawsuit was pending, Dudington's vessel was torched by a Rhode Island mob in what became known as the Gaspee Affair. In the aftermath of the Gaspee Affair, Greene became increasingly alienated from the British. At the same time, Greene drifted away from his father's Quaker faith, and he was suspended from Quaker meetings in July 1773. In 1774, after the passage of measures that colonials derided as the "Intolerable Acts", Greene helped organize a state militia unit known as the Kentish Guards. Because of his limp, Greene was not selected as an officer in the militia.