John Paulet, 5th Marquess of Winchester (c. 1598 – 5 March 1675) was 3rd but eldest surviving son of William Paulet and his successor as 5th Marquess of Winchester. He kept terms at Exeter College, Oxford, but as a Roman Catholic could not matriculate. His chief seat, Basing House, was the great resort of Queen Henrietta Maria's friends in south-west England. On the outbreak of the English Civil War he fortified and garrisoned Basing House and held it for Charles I during 1643 and 1644, until it was stormed by Oliver Cromwell in October 1645. He was committed to the Tower of London on a charge of high treason, 1645, where he remained a long time, and his property sequestered and partially sold. He regained his lands at the Restoration.
To the Royalist side, he was known as "the Great Loyalist."