Sir Hewett Osborne (1567–1599) was an English landowner and soldier who served in Ireland in the late sixteenth century.
He was the son of Edward Osborne, a Lord Mayor of London and Anne, the daughter of prominent merchant Sir William Hewett who had been elected for a standard spell as Lord Mayor of London.
He studied law at the Inner Temple, then in 1590 enlisted for military service as a volunteer in Lord Willoughby's expedition to France to assist Henry IV.
Essex had him knighted for his services at Maynooth but he died the same year in a skirmish with the rebels.
He was succeeded by his son Sir Edward Osborne, 1st Baronet whose eldest son became Duke of Leeds, a leading figure in the early Tory Party in the reign of Charles II and one of the Immortal Seven for his invitation to William and Mary to overthrow his exiled ruling brother (James II and VII).