Maine was a United States Navy ship that sank in Havana Harbor on February 15, 1898, contributing to the outbreak of the Spanish–American War in April. American newspapers, engaging in yellow journalism to boost circulation, claimed that the Spanish were responsible for the ship's destruction. The phrase, "Remember the Maine! To hell with Spain!" became a rallying cry for action. Although the Maine explosion was not a direct cause, it served as a catalyst that accelerated the events leading up to the war.

Maine is described as an armored cruiser or second-class battleship, depending on the source. Commissioned in 1895, she was the first U.S. Navy ship to be named after the state of Maine. Maine and the similar battleship Texas were both represented as an advance in American warship design, reflecting the latest European naval developments. Both ships had two gun turrets staggered en échelon, and full sailing masts were omitted due to the increased reliability of steam engines. Due to a protracted 9-year construction period, Maine and Texas were obsolete by the time of completion. Far more advanced vessels were either in service or nearing completion that year.

Maine was sent to Havana Harbor to protect U.S. interests during the Cuban War of Independence. She exploded and sank on the evening of 15 February 1898, killing 268 sailors, or three-quarters of her crew. In 1898, a U.S. Navy board of inquiry ruled that the ship had been sunk by an external explosion from a mine. However, some U.S. Navy officers disagreed with the board, suggesting that the ship's magazines had been ignited by a spontaneous fire in a coal bunker. The coal used in Maine was bituminous, which is known for releasing firedamp, a mixture of gases composed primarily of flammable methane that is prone to spontaneous explosions. An investigation by Admiral Hyman Rickover in 1974 agreed with the coal fire hypothesis. The cause of her sinking remains a subject of debate.The ship lay at the bottom of the harbor until 1911, when a cofferdam was built around it. The hull was patched up until the ship was afloat, then she was towed to sea and sunk. Maine now lies on the sea-bed 3,600 feet (1,100 m) below the surface. The ship's main mast is now a memorial in Arlington National Cemetery.