William Palfrey (1741 – December 1780) was an American Patriot born in Boston, Massachusetts. Working as John Hancock’s chief clerk, he was active in the movements that preceded the American Revolution, and visited England in 1771. During the War of Independence, Palfrey served as an aide-de-camp to George Washington in March and April 1776, after which Hancock arranged to have him appointed paymaster-general in the Continental Army, with the rank of lieutenant-colonel. In November 1780, he was appointed consul-general in France by a unanimous vote of Congress, and embarked in a ship for that country, which was never heard of after she had left the capes.
His grandson John G. Palfrey was a U.S. Representative from Massachusetts.