HMS St. Vincent was the lead ship of the St. Vincent class battleships of the British Royal Navy.
She was commissioned on 3 May 1910 as 2nd flagship of 1st Division Home Fleet at Portsmouth. She was commanded by Capt. Douglas Nicholson and was flagship of Rear-Admiral Richard Peirse, M.V.O., Home Fleet, at the Coronation Spithead Review of 24 June 1911.
In April 1914, she became flagship of the Second-in-Command, 1st Battle Squadron Home Fleet, which she remained until November 1915, when she became a private ship. She was in the 5th Division of the battlefleet at the Battle of Jutland, 20th in the line of battle, and engaged a German battleship believed to have been of the König class.
In June 1916, she was transferred to the 4th Battle Squadron. In March 1919, she was reduced to reserve and became a gunnery training ship, which she remained until placed on the Disposal list in March 1921. She was sold for scrap in 1921.