Col. Isaac Allerton Jr. (ca. 1627 / 1630 – December 30, 1702) was planter, military officer, politician and merchant in colonial America. Like his father, he first traded in New England, and after his father's death, in Virginia. There, he served on the Governor's Council (1687-1691) and for many years in the House of Burgesses, representing Northumberland County and later Westmoreland County.