Sir Robert Holborne (died 1647) was an English lawyer and politician, of Furnival's Inn and Lincoln's Inn (where he was bencher and reader in English law). He acted, along with Oliver St. John, as co-counsel for John Hampden in the ship money case. He sat in the House of Commons between 1640 and 1642 and supported the Royalist cause in the English Civil War. He was attorney-general to the Prince of Wales, being knighted in 1643. He also published legal tracts.
Holborne was the son of Nicholas Holbone of Chichester. His mother was, perhaps, Anne, sister of John Lane. Holborne was married (1630-3) to the Lady Anne Dudley, granddaughter of the famous Earl of Leicester. Lady Anne was one of the abandoned daughters and co-heirs of Sir Robert Dudley, formally of Kenilworth Castle, Warwickshire. It has been suggested this relationship may have influenced his initial anti-Court reputation.
He was trained for the law, as the custom then was, at Furnival's Inn, before proceeding to Lincoln's Inn, where he entered 9 November 1615, and subsequently became a bencher and reader in English law there. He was early distinguished in practice at the king's bench, and his opinion was taken by John Hampden in regard to ship-money. In the great case he was one of Hampden's counsel, and supplied what Oliver St John had omitted in an elaborate argument which lasted for three days, 2–5 December 1637.
In April 1640 Holborne was elected Member of Parliament for Southwark in the Short Parliament. In November 1640, he was elected MP for St. Michael, Cornwall, in the Long Parliament. While in the house he spoke strongly in favour of the power of convocation to bind the laity, in so far as the canons did not conflict with the law of the land.