A Ribauldequin, also known as a rabauld, ribault, ribaudkin, or organ gun, was a medieval volley gun with many small-caliber iron barrels set up parallel on a platform, which, when fired, were somewhat akin to machine guns of modern times. They are sometimes (incorrectly) identified as early or even the earliest machine gun. When the gun was fired in a volley, it created a shower of rapid iron shot. They were employed, specifically, during the early fifteenth century, and continued serving, mostly, as an anti-personnel gun.

The first known ribauldequin was used by the army of Edward III of England in 1339 in France during the Hundred Years War. Edward's ribauldequins had twelve barrels which fired salvoes of twelve balls. Later on, Milan and several other wealthy and technologically advanced areas used a nine-barreled ribault.

Ribauldequins were also used in the Wars of the Roses. During the Second Battle of St Albans, Burgundian soldiers under Yorkist control utilized the weapon against the Lancastrian Army led by Queen Margaret of Anjou.

The Swiss Army was also known to employ organ guns in battle, notably at the Battle of Sempach, even developing early firearms from them.

In Eastern Europe, a heavier version of the organ gun was used by Stephen the Great of Moldavia as late as 1475, as attested to by Polish chronicler Bieski.