Captain John Luttrell-Olmius, 3rd Earl of Carhampton (11 December 1739 – 19 March 1829), styled The Honourable John Luttrell between 1768 and 1787 and as The Honourable John Luttrell-Olmius between 1787 and 1829, was an Irish naval commander and politician who sat in the House of Commons between 1774 and 1785.