Alexander Henry 'The Elder', in French: Alexandre Henri Le Vieux (August 1739 – 4 April 1824) was an American-born explorer, author, merchant who settled in Quebec following the Conquest of New France and was a partner in the North West Company and a founding member and vice-chairman of the Beaver Club. From 1763 to 1764, he lived and hunted with Wawatam of the Ojibwe, who had adopted him as a brother.

"Blessed with as many lives as a cat", he recounted his time with the Ojibwe and subsequent explorations in his Travels and Adventures in Canada and the Indian Territories between the years 1760 and 1776 (published in New York City in 1809), which he dedicated to his friend Sir Joseph Banks. The book is considered an adventure classic and one of the best descriptions of Native Indian life at this time.

An "easy and dignified" raconteur, in 1776 Henry was invited to give an account of his journeys at the Royal Society in London and at Versailles to Queen Marie Antoinette. In the 1780s, Henry introduced John Jacob Astor into the North American fur trade; subsequently, Astor would stay as Henry's guest during his annual visits to Montreal.

Alexander Henry was born at New Brunswick, New Jersey, to an educated merchant family related to Matthew Henry. His father was from England and his mother was from Wales. He was the eldest son of John Henry (d. 1766), a merchant whose father, Alexander Henry (d. 1744), had emigrated to British North America from the West of England to seek his fortune. He received a good education and afterward took an apprenticeship in business. From the age of twenty, Henry was working as a merchant out of Albany, New York. He made a lucrative but hazardous living supplying the British army during the French and Indian War (the North American front of the Seven Years' War). In 1760, after Wolfe's victory at the Battle of the Plains of Abraham, Henry was placed in charge of three loaded supply bateaux, which followed Lord Amherst's advance along Lake Ontario to Montreal. In 1760, Henry was the first British subject known to have visited the area of Milwaukee.

In early 1761, at Les Cèdres, Henry met the former fur trader Jean-Baptiste Leduc, who acquainted him with the rich possibilities of trading at Michilimackinac and around Lake Superior. That spring at Montreal, he secured a fur trade pass from Thomas Gage, the second British subject (by only a few days) to do so. Henry wrote, "proposing to avail myself of the new market, which was thus thrown open to British adventure, I... procured a quantity of goods" and set out on the Ottawa River to Fort Michilimackinac. As he was "altogether a stranger to the commerce in which (he) was engaging," he stopped while still in Canada to hire a guide, Etienne-Charles Campion, an experienced voyageur.

In 1761, as they travelled west, Henry was repeatedly warned by the Indians they encountered not to risk his life among the Ojibwe, who remained fiercely loyal to the French. When Henry took the warnings seriously, he did not have enough supplies to turn back. He disguised himself as a voyageur and let Campion pass for the proprietor. No one was fooled. When he arrived among the Ojibwe at Michilimackinac, Henry found himself surrounded by sixty of their warriors, "each with his tomahawk in one hand, and scalping knife in the other." The imposingly tall war chief Mihnehwehna reminded him that the British may have conquered the French, but they had not conquered the Ojibwe. After capturing New France, the British had neglected to make peace with the Indian allies of the French. Having put to use all of his diplomatic skills for which he would become well known, Henry "inwardly endured the tortures of suspense" before Mineweh declared that he admired Henry's bravery for entering their lands. He said since Henry did not come intending to make war, he could "sleep tranquilly" among them. That winter of 1761–62, a minor Ojibwe chief, Wawatam, adopted Henry as a brother. Henry described the Ojibwe as "peaceful", "wholesome", "kind" and "trustworthy" and said that he had a "great and deep respect" for them.

Henry's ability to make friends with both the French and their allied Indians greatly facilitated his trading activities. Between 1762 and 1763, Henry did business at Sault Ste Marie, where he formed friendships with Jean Baptiste Cadot. (father of Michel Cadotte) and Sir Robert Davers. However, when they returned to Michilimackinac, Chief Pontiac had already launched a pan-tribal offensive against British outposts in the Ohio Country. The Ojibwe warriors attacked Fort Michilimackinac. Danvers was killed and Henry, after hiding for a time in the house of Charles Michel de Langlade, was captured by the Ojibwe.

On June 6, Henry and three other British prisoners were taken by canoe toward Beaver Island. As they reached Waugoshance Point, an Odawa tribal appeared and spoke with them, luring them close to land. Several Odawa warriors sprang from cover and charged the canoe, forcibly removing the four prisoners, who were taken back to Mackinac.