SS London was a British steamship which sank in the Bay of Biscay on 11 January 1866.
The final voyage of the London began on 13 December 1865, when the ship left Gravesend in Kent bound for Melbourne, under a Captain Martin, an experienced Australian navigator. A story later highly publicised after the loss states that when the ship was en route down the Thames, a seaman seeing her pass Purfleet said: "It'll be her last voyage…she is too low down in the water, she'll never rise to a stiff sea." This proved all too accurate.
The ship was overloaded with cargo, and thus unseaworthy, and only 19 survivors were able to escape the foundering ship by lifeboat, leaving a death toll of 220.
The loss of the London increased attention in Britain to the dangerous condition of the coffin ships, overloaded by unscrupulous ship owners, and the publicity had a major role in Samuel Plimsoll's campaign to reform shipping so as to prevent further such disasters. The disaster helped stimulate Parliament to establish the famous Plimsoll line, although it took many years.