A messer (German for "knife") is a single-edged sword of the 15th and 16th century, characterised by knife-like hilt construction methods.

Hilts are normally suited to single handed use, but the larger examples may feature extended grips suitable for a second hand-hold.

Designed to be used with both hands, such messers were dedicated military arms, normally wielded by professional soldiers during the 15th and 16th century, such as the Landsknecht.

Messer appear to have emerged in the region of Southern Germany, Switzerland, or Northern Austria in the first few years of the 15th century, as small Bauernwehr and Hauswehr civilian knives of low social status.

The geographical spread of messers can be traced from known centres of manufacture in areas like Passau and Solingen, through medieval river trade routes, and the shipping networks of the Hanseatic League.

Most messer are assembled with the hilt consisting of a slab tang sandwiched between two wooden grip plates which are pinned or riveted into place.

Messer usually feature a Nagel: a nail-like protrusion which projects out from the right side of the cross-guard perpendicular to the flat of the blade, which protects the knuckles of the wielder's hand from injury.