William Dummer was a politician in the Province of Massachusetts Bay. He served as its lieutenant governor for fourteen years (1716–1730), including an extended period from 1723 to 1728 when he acted as governor. He is remembered for his role in leading the colony during what is sometimes called Dummer's War, which was fought between the British colonies of northeastern North America and a loose coalition of native tribes in what is now New Hampshire, Maine, New Brunswick, and Nova Scotia.

The Province of Massachusetts Bay was a colony in New England which became one of the thirteen original states of the United States. It was chartered on October 7, 1691, by William III and Mary II, the joint monarchs of the kingdoms of England, Scotland, and Ireland, and was based in the merging of several earlier British colonies in New England. The charter took effect on May 14, 1692, and included the Massachusetts Bay Colony, the Plymouth Colony, the Province of Maine, Martha's Vineyard, Nantucket, Nova Scotia, and New Brunswick; the Commonwealth of Massachusetts is the direct successor. Maine has been a separate state since 1820, and Nova Scotia and New Brunswick are now Canadian provinces, having been part of the colony only until 1697.