NAVARINO, or Neocastro, a seaport of the Morea, Greece, in the nomarchy of Messenia, stands on the south shore of the Bay of Navarino, in 36° 54' N. lat. and 21° 4Γ E. long. It consists of a citadel, situated on a high rock, and a lower town,—the whole being surrounded by a wall. The population is under 2000. The bay, one of the best harbours in Greece, about 4 miles in length by 2 in breadth, with a depth ranging from 12 to 26 fathoms, is protected towards the west by the long and narrow island of Sphagia, the ancient Sphacteria, to the south-east of which lies the entrance, now nearly a mile wide, but anciently much narrower (Thucyd. iv. 8).

The word Navarino is explained as equivalent to Avarino, and is said to record an Avar settlement made here in the 6th century. The name Neocastro distinguishes the place from Palaeocastro, the alleged site of the ancient Pylus, on the northern shore of the bay. Sphacteria was the scene of the famous blockade and defeat of the Spartans in 425 B. c.; and it was by the victory of the combined fleets of Great Britain, France, and Russia over those of Turkey and Egypt in the Bay of Navarino on October 27, 1827, that the independence of Greece was virtually secured.