Sarah Ann Island (also spelled Sarah Anne) is a vanished island, previously located at 4°0′N 154°22′WCoordinates: 4°0′N 154°22′W[1] (though sometimes listed at about 175° W[2]). It was discovered in 1858 and claimed by an American guano firm, under the Guano Islands Act (as Sarah Anne).

A search in 1932 by German astronomers was unsuccessful.[4] In 1937, the United States Pacific Fleet attempted to locate the island, intending to establish an observatory there to view the solar eclipse of June 8, 1937, but was also unsuccessful. The island, which was observed 15 years before, was nowhere to be found. Instead, observations were made on the nearby Canton and Enderbury Islands and Sarah Ann was quietly removed from Naval charts and has become a phantom island.

One explanation is that Sarah Ann Island was identical to Malden Island, but due to a clerical error it was listed at 4° N instead of 4° S.