The A-91 is a bullpup assault rifle developed during the 1990s by KBP Instrument Design Bureau in Tula, Soviet Union as an offspring of the 9A-91 firearm family.

It is an evolution of the earlier 9A-91 carbine, primarily designed to be compact, reliable, and versatile in urban combat scenarios.

The rifle is notable for its integrated 40mm grenade launcher and the use of a bullpup configuration, which positions the magazine behind the trigger, allowing for a more compact design without sacrificing barrel length.

However, unlike most Russian rifles, it adopts a bullpup layout, which reduces the overall length while maintaining a full-length barrel, improving handling in confined spaces.

The bullpup design was chosen for its compact size and ease of handling in close-quarter combat (CQB).