SS Andrea Doria pronounced [andra drja], was an ocean liner for the Italian Line (Societ di navigazione Italia) home-ported in Genoa, Italy, known for its sinking in 1956, where of the 1,706 passengers and crew, 1,660 were rescued, while 46 passengers and crew lost their lives.

Named after the 16th-century Genoese admiral Andrea Doria, the ship had a gross register tonnage of 29,100 and a capacity of about 1,200 passengers and 500 crew. For a country attempting to rebuild its shattered economy and reputation after World War II, Andrea Doria was an icon of Italian national pride. Of all Italy's ships at the time, Andrea Doria was the largest, fastest and supposedly safest. Launched on 16 June 1951, the ship began her maiden voyage on 14 January 1953.

On 25 July 1956, while Andrea Doria was approaching the coast of Nantucket, Massachusetts, United States, bound for New York City, the eastbound Stockholm of the Swedish American Line collided with her in one of history's most infamous maritime disasters. Struck in the side, the top-heavy Andrea Doria immediately started to list severely to starboard, which left half of her lifeboats unusable. The consequent shortage of lifeboats could have resulted in significant loss of life, but the ship stayed afloat for over 11 hours after the collision. The calm, appropriate behavior of the crew, together with improvements in communications, and the rapid response of other ships, averted a disaster similar in scale to that of Titanic in 1912. While 1,660 passengers and crew were rescued and survived, 46 people on the ship died as a direct consequence of the collision. The evacuated luxury liner capsized and sank the following morning. This accident remains the worst maritime disaster to occur in United States waters since the capsizing of the Eastland in Chicago in 1915.The incident and its aftermath were heavily covered by the news media. While the rescue efforts were both successful and commendable, the cause of the collision with Stockholm and the loss of Andrea Doria generated much interest in the media and many lawsuits. Largely because of an out-of-court settlement agreement between the two shipping companies during hearings immediately after the disaster, no determination of cause was ever formally published. Although greater blame appeared initially to fall on the Italian liner, more recent discoveries have indicated that a misreading of radar on the Swedish ship initiated the collision course, leading to errors on both ships.

Nantucket is an island about 30 miles (50 km) by ferry south from Cape Cod, in the U.S. state of Massachusetts. Together with the small islands of Tuckernuck and Muskeget, it constitutes the Town and County of Nantucket, a combined county/town government. It is the only such consolidated town-county in Massachusetts. As of the 2020 census, the population was 14,255, making it the least populated county in Massachusetts. Part of the town is designated the Nantucket CDP, or census-designated place. The region of Surfside on Nantucket is the southernmost settlement in Massachusetts.

The name "Nantucket" is adapted from similar Algonquian names for the island, but is very similar to the endonym of the native Nehantucket tribe that occupied the region at the time of European settlement.Nantucket is a tourist destination and summer colony. Due to tourists and seasonal residents, the population of the island increases to at least 50,000 during the summer months. The average sale price for a single-family home was $2.3 million in the first quarter of 2018.The National Park Service cites Nantucket, designated a National Historic Landmark District in 1966, as being the "finest surviving architectural and environmental example of a late 18th- and early 19th-century New England seaport town."