The Mysterious Island (French: L'Île mystérieuse) is a novel by Jules Verne, serialised from August 1874 to September 1875 and then published in book form in November 1875.

The novel is a crossover sequel to Verne's famous Twenty Thousand Leagues Under the Seas (1870) and In Search of the Castaways (1867–68), though its themes are vastly different from those books.

The escapees are Cyrus Smith, a railroad engineer in the Union army (named Cyrus Harding in Kingston's translation); his ex-slave and loyal follower Neb (short for Nebuchadnezzar); Bonadventure Pencroff, a sailor (who is addressed only by his surname; in Kingston's version, he is named Pencroft); his protégé and adopted son Harbert Brown (called Herbert in some translations); and the journalist Gedéon Spilett (Gideon Spilett in English versions).

With the knowledge of the brilliant engineer Smith, the five are able to sustain themselves on the island, producing fire, pottery, bricks, nitroglycerin, iron, an electric telegraph, a cave home inside a stony cliff called "Granite House", and even a seaworthy ship, which they name the "Bonadventure".

During their stay on the island, the "colonists" endure bad weather and domesticate an orangutan, Jupiter, abbreviated to Jup (or Joop, in Jordan Stump's translation).

Having escaped the maelstrom at the end of Twenty Thousand Leagues Under the Seas, the Nautilus sailed the oceans of the world until all its crew except Nemo had died.

After taking part in the failed Indian Rebellion of 1857, Prince Dakkar escaped to a desert island with twenty of his compatriots and commenced the building of the Nautilus and adopted the new name of "Captain Nemo".

However, it is now known that the translator of Mysterious Island and his other Verne novels was actually his wife, Agnes Kinloch Kingston, who had studied on the continent in her youth.

In addition many technical passages were abridged or omitted and the anti-imperialist sentiments of the dying Captain Nemo were purged so as not to offend English readers.

This translation is more faithful to the original story and restores the death scene of Captain Nemo, but there is still condensation and omission of some sections such as Verne's description of how a sawmill works.

Kravitz also translated Shipwrecked Family: Marooned With Uncle Robinson, published by the North American Jules Verne Society and BearManor Fiction in 2011.

According to Mortelier, Verne read Raynal's account and loosely based his novel on the true life story of Grafton shipwreck, survival, privation, and ultimate rescue.