Montague John Guest (29 March 1839 – 9 November 1909), was a British Liberal politician.

A member of the prominent Guest family, he was the third son of Sir John Josiah Guest, 1st Baronet, and his second wife Lady Charlotte, daughter of Albemarle Bertie, 9th Earl of Lindsey.

He entered Parliament for Youghal in a 1869 by-election, a seat he held until 1874, and later represented Wareham from 1880 to 1885.

Guest was associated with freemasonry from 1867, and served as Provincial Grand Master of Dorset Freemasons until he resigned in 1902.

He was librarian of the Royal Yacht Squadron,[2] and wrote Memorials of the Royal Yacht Squadron in 1902.