The lorica segmentata was a type of armour primarily used in the Roman Empire, exploiting Hellenistic Greek technology, but the Latin name was first used in the 16th century (the ancient form is unknown). The armour itself consist of broad ferrous (iron or steel) strips ('girth hoops') fastened to internal leather straps. The strips were arranged horizontally on the body, overlapping downwards, and they surrounded the torso in two halves, being fastened at the front and back. The upper body and shoulders were protected by additional strips ('shoulder guards') and breast- and backplates. The form of the armour allowed it to be stored very compactly, since it was possible to separate it into four sections. During the time of its use, it was modified several times, the currently recognised types being the Kalkriese (c. 20 B.C. to A.D. 50), Corbridge (c. A.D. 40 to A.D. 120), and Newstead (c. A.D. 120 to 250) types.

The main problem with the lorica segmentata was its complexity, making its components prone to attrition and corrosion.

So far as is known, only legionaries (heavy infantry of the Roman Legions) were issued with the lorica segmentata. Auxiliary forces would more commonly used the Lorica Hamata which is mail (frequently called chainmail) or Lorica Squamata (scale armor).

It fell out of use during the 3rd century A.D., but similar armouring techniques were used during the 16th century, employing sliding rivets and this was known as Anima.