A maritime disaster is an event which usually involves a ship or ships and can involve military action. Because of the nature of maritime travel, there is often a substantial loss of life. The term maritime disaster can refer to both commercial ships and military naval ships. A maritime disaster can result in one or more of the following simultaneously; Loss of life Pollution of marine environment (in case of oil spill, foul discharge of materials, sulphur emitted from fuels, etc.) Degradation of the aquatic ecosystem Economic loss at a grand scale Destruction of onshore properties (accidents at harbor are not only limited to the vessels but also damage the nearest lands) There are countless incidents reported on marine disasters.

The sinking of the British ocean liner in 1912, is probably the most famous shipwreck, but not the most catastrophic in terms of lives lost. The wartime sinking of the German in January 1945 in World War II by a Soviet Navy submarine, with an estimated loss of about 9,400 people, remains the deadliest isolated maritime disaster ever, excluding such events as the destruction of entire fleets like the 1274 and 1281 storms that are said to have devastated Kublai Khan's fleets in his invasions of Japan. The 1987 loss of the Philippine ferry Doña Paz, with an estimated 4,386 dead, is the largest peacetime loss recorded.

Peacetime All ships, including those of the military, are vulnerable to problems from weather conditions, faulty design or human error. The disasters listed below were not related directly to military action, though some of them occurred during periods of conflict. The table listings are in decreasing order with respect to the number of casualties.