RMS Titanic was a British passenger liner operated by the White Star Line that sank in the North Atlantic Ocean in the early morning hours of 15 April 1912, after striking an iceberg during her maiden voyage from Southampton to New York City. Of the estimated 2,224 passengers and crew aboard, more than 1,500 died, making the sinking one of modern history's deadliest peacetime commercial marine disasters. RMS Titanic was the largest ship afloat at the time she entered service and was the second of three Olympic-class ocean liners operated by the White Star Line. She was built by the Harland and Wolff shipyard in Belfast. Thomas Andrews, chief naval architect of the shipyard at the time, died in the disaster.

Titanic was under the command of Capt. Edward Smith, who also went down with the ship. The ocean liner carried some of the wealthiest people in the world, as well as hundreds of emigrants from Great Britain and Ireland, Scandinavia and elsewhere throughout Europe, who were seeking a new life in the United States. The first-class accommodation was designed to be the pinnacle of comfort and luxury, with a gymnasium, swimming pool, libraries, high-class restaurants and opulent cabins. A high-powered radiotelegraph transmitter was available for sending passenger "marconigrams" and for the ship's operational use. Although Titanic had advanced safety features, such as watertight compartments and remotely activated watertight doors, it only carried enough lifeboats for 1,178 people—about half the number on board, and one third of her total capacity—due to the maritime safety regulations of those days. The ship carried 16 lifeboat davits which could lower three lifeboats each, for a total of 48 boats. However, Titanic carried only a total of 20 lifeboats, four of which were collapsible and proved hard to launch during the sinking.

The wreck of Titanic was discovered in 1985 (more than 70 years after the disaster) during a Franco-American expedition and US military mission.The ship was split in two and is gradually disintegrating at a depth of 12,415 feet (2,069.2 fathoms; 3,784 m). Thousands of artefacts have been recovered and displayed at museums around the world. Titanic has become one of the most famous ships in history, depicted in numerous works of popular culture, including books, folk songs, films, exhibits, and memorials. Titanic is the second largest ocean liner wreck in the world, only being surpassed by her sister ship HMHS Britannic, however, she is the largest sunk while in service as a liner, as Britannic was in use as a hospital ship at the time of her sinking. The final survivor of the sinking, Millvina Dean, aged two months at the time, died in 2009 at the age of 97.