Sir Henry Wallop (c. 1540 – 14 April 1599) was an English statesman.
He was the eldest son of Sir Oliver Wallop (d. 1566) of Farleigh Wallop in Hampshire. Having inherited the estates of his father and of his uncle, Sir John Wallop, he was knighted in 1569 and was chosen member of parliament for Southampton in 1572. His connection with Ireland, began in 1579, when he was appointed vice-treasurer of that country; this position was a very thankless and difficult one, and Wallop appears to have undertaken it very unwillingly.
However, he reached Dublin and was soon immersed in the troubles caused by the rebellion of Gerald FitzGerald, 15th Earl of Desmond, finding, in his own words, it was "easier to talk at home of Irish wars than to be in them." In July 1582 he and Adam Loftus, archbishop of Dublin, were appointed Lord Justices (Ireland), and they were responsible for the government of Ireland for just two years, after which they were succeeded by Sir John Perrot.
Sir Henry continued to fill the office of vice-treasurer, and at Enniscorthy, where he had secured a lease of lands, he set up a colony of Englishmen and opened up a trade with Madeira. As a member of the Irish council he quarrelled with Perrot, and then from 1589 to 1595 he was in England, entertaining the queen at Farleigh Wallop in 1591. Having returned to Ireland he was sent to Dundalk to attempt to make peace with Hugh O'Neill, earl of Tyrone, but this proved a vain errand. At length, after many entreaties, he was allowed to resign the treasurership, but before he could arrange to leave Ireland he died.
Wallop's eldest son, Sir Henry Wallop (1568-1642), who acted as his father's deputy in Ireland, left an only son, Robert Wallop (1601-1667). A member of parliament for nearly forty years, and a supporter of the parliamentary party during the English Civil War, Robert was one of the judges of Charles I, although he did not sign the death warrant. He was active under the Commonwealth, being a member of nearly all the councils of state. At the restoration he was deprived of his estates and was imprisoned, and he died in the Tower of London on 19 November 1667. Robert's son Henry (d. 1673) was the grandfather of John Wallop, 1st Earl of Portsmouth.