Admiral Frederick Beauchamp Paget Seymour, 1st Baron Alcester, GCB (12 April 1821 – 30 March 1895) was a British naval commander.

He was the Commander-in-Chief of the Australia Station from 10 March 1860 and 21 July 1862 as Commodore second class with his pennant aboard Pelorus.

From 1868 to 1870 Seymour served as private secretary to the First Lord of the Admiralty, Hugh Childers, and was promoted to Rear-Admiral.

In 1872, he became Fourth Naval Lord for two years, and then commander of the Channel Squadron.

He became a vice-admiral on 31 December 1876, and was appointed KCB in June 1877, and was promoted to GCB on 24 May 1881.