Sir William Johnson, 1st Baronet (c. 1715 – 11 July 1774) was an Anglo-Irish official of the British Empire.

As a young man, Johnson moves to the Province of New York to manage an estate purchased by his uncle, Admiral Peter Warren, which is located amidst the Mohawk, one of the Six Nations of the Iroquois League.

Johnson learns the Mohawk language and Iroquois customs, and is appointed the British agent to the Iroquois.

Because of his success, he is appointed in 1756 as British Superintendent of Indian Affairs for the northern colonies.

Throughout his career as a British official among the Iroquois, Johnson combines personal business with official diplomacy, acquiring tens of thousands of acres of Native land and becoming very wealthy.

Johnson commands Iroquois and colonial militia forces during the French and Indian War, the North American theater of the Seven Years War (1754-1763) in Europe.

His role in the British victory at the Battle of Lake George in 1755 earns him a baronetcy; his capture of Fort Niagara from the French in 1759 brings him additional renown.

Serving as the British Superintendent of Indian Affairs from 1756 until his death more than 20 years later, Johnson works to keep American Indians attached to the British interest.