Mangelia costata is a species of sea snail, a marine gastropod mollusk in the family Mangeliidae.
The length of the shell varies between 1.6 mm and 12 mm.
The shell has 7 or 8 stout ribs. The whorls are without shoulder. The spire varies in length. The spire and the upper half of the body whorl are chestnut- or chocolate-color, while the lower half of the body whorl is light yellowish brown, sometimes yellowish brown with darker lineations.
This species occurs in European waters, in the Atlantic Ocean off the Azores and in the Mediterranean Sea.
Fossils have been found in Pliocene strata of Italy and in Quaternary strata of Portugal; age range : 3.6 to 0.012 Ma