Worsley, Benjamin (1617/18–1677), administrator, was born and educated in London, the eldest son of Francis Worsley of Kenton, Warwickshire, and his wife, Mary, daughter of Shipman Hopkins of Coventry. By 1640 he was in Ireland serving in the household of Thomas Wentworth (qv), lord lieutenant of Ireland, and in 1641 became surgeon general in the Irish army. Lacking a formal education, he entered Trinity College, Dublin, in 1643, at the age of twenty-five, but given that most of Ireland was in rebellion, the time was not suitable for study. He was in London by May 1644, where he developed a reputation as a projector through his scheme for manufacturing saltpetre. In summer 1646 he played the main role in creating the ‘Invisible College’, an intellectual group that promoted the study of science. In July 1647 the Long parliament reappointed him surgeon general to the army in Ireland, but instead of taking up his post he went to study for two years in the Dutch republic.
Worsley returned to England in 1649 and became associated with several leading members of the Rump parliament, including Sir Henry Vane the younger. Appointed secretary to the council of trade in August 1650, he claimed to have been the prime mover in the passing of the Navigation Act of 1651. In 1652 he became secretary to the parliamentary commissioners in Ireland, but he relinquished this post in 1653 in an unsuccessful bid to join a government embassy to Sweden. However, a new position was soon found for him and he returned to Dublin as surveyor general of forfeited estates. As such, he was faced with the monumental task of surveying the vast amount of land that had been confiscated from catholic landowners after the Cromwellian conquest of Ireland. In the event, Worsley's position was undermined by his great professional rival William Petty (qv), who in 1654 supplanted him in the role of surveyor of confiscated estates. The two men were engaged in a personal feud from 1652 at the latest, and Worsley's reputation suffered from Petty's far from disinterested criticism of his work in surveying the Irish lands.
During the 1650s Worsley's talents were poorly utilised by the Dublin administration, which regarded his radical political and religious views with suspicion. He opposed the suppression of the Rump parliament in 1653 and retained his links with republicans such as Vane. As a result, in 1658, Petty, who enjoyed the patronage of Henry Cromwell (qv), lord deputy of Ireland from 1656 to 1659, was able to veto Worsley's scheme to endow a scientific research institute out of the sale of Irish land debentures and to secure his dismissal as surveyor general. Nonetheless, in 1657 he was granted land, probably in Queen's County where he was a justice of the peace. Following the collapse of the protectorate in 1659, Worsley briefly came back into favour, being appointed commissary of the general muster in Ireland. During this period he also abetted unsuccessful efforts to impeach Petty and Henry Cromwell. In 1659 he cut his ties with Ireland, selling his land and returning to England.
After the restoration of the monarchy Worsley settled in Tuthill Fields in London and concentrated on economic and commercial issues. Between 1668 and 1673 he was heavily involved in advising the government on such matters, serving as commissioner of trade (1668–69), assistant secretary of the council of foreign plantations (1670–72), and secretary and treasurer of the council of trade and foreign plantations. He died in 1677. He had married, in 1656, Lucy, daughter of William Cary of Dartmouth, Devon.