James Wilkinson (March 24, 1757 – December 28, 1825) was an American army officer and politician who was associated with multiple scandals and controversies during his life, including the Burr conspiracy. He served in the Continental Army during the American Revolutionary War, but he was twice compelled to resign. He was twice the Senior Officer of the U.S. Army; was appointed to be the first governor in the newly acquired western lands of the Louisiana Purchase of 1803, later organized by the United States Congress and the third President, Thomas Jefferson as the Louisiana Territory in 1804–1812, west of the Mississippi River; and commanded two unsuccessful military invasion campaigns in the St. Lawrence River valley theater in Canada during the War of 1812.

He died while seeking to serve as an envoy diplomat in Mexico City, the capital of the newly declared independent Mexico. Four decades later in 1854, following extensive archival research in Spanish royal archives at Madrid, the American historian Charles Gayarré, found documents which exposed Wilkinson as having been a highly paid Spanish spy. In the years since Gayarré's research became public, Wilkinson has been savagely condemned by subsequent American academic historians and politicians. 26th President Theodore Roosevelt claimed "[I]n all our history, there is no more despicable character."

James Wilkinson was born on March 24, 1757, the son of Joseph Wilkinson and Alethea (Heighe) Wilkinson. Wilkinson's birthplace was about three miles (5 km) northeast of Benedict, Charles County, Maryland, on a farm south of Hunting Creek in Calvert County.

Wilkinson's grandfather had been sufficiently wealthy to buy a large property known as Stoakley Manor in Calvert County. Even though James Wilkinson's family lived on a smaller estate than those of Maryland's elite, they still saw themselves as members of the higher social class. According to the historian Andro Linklater, Wilkinson grew up with the idea that "the image of respectability excused the reality of betrayal". His father inherited Stoakley Manor, but by then the family was in debt. Joseph Wilkinson died in 1763, and in 1764 Stoakley Manor was broken up and sold. Wilkinson's older brother, Joseph, inherited what was left of the manor property after his father died. As the second son, James Wilkinson inherited no land.

Wilkinson's father had left him with the last words "My son, if you ever put up with an insult, I will disinherit you." Andro Linklater argued that this upbringing led to Wilkinson's aggressive reaction toward perceived insults. Wilkinson's early education by a private tutor was funded by his maternal grandmother. His study of medicine at the University of Pennsylvania, also funded by his grandmother, was interrupted by the American Revolutionary War.

Wilkinson married Ann Biddle (1742–1807) of the prominent Biddle family of Philadelphia on November 12, 1778, in Philadelphia. She was a first cousin of Charles Biddle, an associate of Aaron Burr, and Wilkinson's marriage to the dynamic Biddle helped his career as a politician and general. She died on February 23, 1807.

The couple had four sons: John (1780–1796), James Biddle (c. 1783–1813), Joseph Biddle (1785–1865), and Walter (born 1791). James and Walter both served as captains in the U.S. Army.

On March 5, 1810, Wilkinson married Celestine Laveau Trudeau, widow of Thomas Urquhart and daughter of Charles Laveau Trudeau. They were the parents of twin girls Marie Isabel and Elizabeth Stephanie as well as a son, Theodore. Celestine's father, known in Louisiana as Don Carlos Trudeau, had served in the Spanish government of New Orleans. When the United States gained control of the city, he remained in New Orleans and anglicized his name.