William Randolph built a career as a planter, merchant, and officeholder in late seventeenth-century Virginia. After emigrating from England, he accumulated land in Henrico County and established his principal residence at Turkey Island on the James River. Tobacco cultivation and overseas trade provided the foundation of his wealth. His shipping connected his plantations with English markets, especially Bristol, while his holdings extended across several estates.

Randolph held local responsibilities as county clerk and militia officer before serving in the House of Burgesses for Henrico from 1684 to 1698. He became Speaker in 1698 and also served as a clerk of the House. His legal and administrative appointments placed him within the small circle of men who combined substantial property with political influence. In 1693 he was named among the trustees of the newly chartered College of William and Mary, supporting the colony's effort to establish a college.

His plantations depended on bound labor, including enslaved Africans and indentured servants, and his expanding holdings formed part of Virginia's increasingly slave-based economy. Marriage to Mary Isham strengthened his place among prominent colonial families. At his death in 1711 he left extensive property to his children, whose marriages and inheritances spread the family's connections. His career combined the management of land, trade, labor, and office, before the prominence of the descendants associated with his name.