Stephen Moylan (1737 – April 11, 1811) was an Irish American patriot leader during the American Revolutionary War. He had several positions in the Continental Army including Muster-Master General, Secretary and Aide to General George Washington, 2nd Quartermaster General, Commander of The Fourth Continental Light Dragoons and Commander of the Cavalry of the Continental Army.
In January 1776, he wrote a letter using the term "United States of America", the earliest known use of that phrase.
Stephen Moylan was born to a prominent Catholic family in Cork, Ireland. His family sent him to be educated in Paris. Moylan then worked in Lisbon for three years in the family shipping firm. He settled in Philadelphia in 1768 to organize his own shipping firm. He was one of the organizers of the Friendly Sons of St. Patrick, an Irish-American fraternal organization, and served as its first president.
Moylan joined the American Continental Army in 1775 and was appointed Muster-Master General on August 11, 1775. Although his experience in the shipping industry afforded the United States a well qualified ship outfitter, who would help fit out the first ships of the Continental Navy. On March 5, 1776, he became secretary to General George Washington. He was promoted to Colonel and was appointed Quartermaster General in the American Continental Army on June 5, 1776. He resigned from this office on September 28, 1776. However, he continued to serve as a volunteer of General Washington's staff through December 1776.