Adam Stephen (c. 1718 – 16 July 1791) was a Scottish-born doctor and military officer who helped found what became Martinsburg, West Virginia. He emigrated to North America, where he served in the Province of Virginia's militia under George Washington during the French and Indian War. He served under Washington again in the American Revolutionary War, rising to lead a division of the Continental Army. After a friendly fire incident during the Battle of Germantown, Stephen was cashiered out of the army, but continued as a prominent citizen of western Virginia, including terms in the Virginia General Assembly representing Berkeley County.