The second HMS Monmouth was a 66-gun third-rate warship of the British Royal Navy, named for the town of Monmouth in Wales. She served from 1667 to 1767, winning ten battle honours over a century of active service.

She was built at Chatham Dockyard in 1667 - seeing action whilst still in the Thames, during the Raid on the Medway, and fought at the Battle of Solebay in 1672, shortly followed by the Battle of Texel in 1673. She fought at the Battle of Barfleur in 1692, at the Battle of Vigo Bay in 1702, and at the Siege of Gibraltar and Velez Malaga in 1704.

Later, in 1747, she fought at Finisterre and Ushant, at Foudroyant in 1758 and Belle Isle in 1761.

After a hundred years of honourable service, she was finally broken up in 1767; a newspaper of the time gave her epitaph as "There was no ship she ever chased that she did not overtake: there was no enemy she ever fought that she did not capture".