The jezail (or jezzail), also spelled juzail (or juzzail), is a long-barrelled weapon used in Central Asia, British India, and parts of Middle East. A person operating it is called jazailchi.

Jezails were used by the elite jazayerchi troops of Safavid and Afsharid Iran, notably during the Naderian Wars. It was the main weapon used by the various ethnic tribesmen of Afghanistan in the 19th-century, who deposed Shah Shuja and fought in the First and Second Anglo-Afghan Wars.

Jezails (in Afghanistan) were often handmade weapons. That means, unlike other weapons of the time which were plain and utilitarian, jezails were tended to be well-crafted, personal, and each varied widely in their construction (and decoration).

Jezails have very long barrels, which is uncommon in European counterparts (aside from the Spanish espingarda [es] of the 15th century), but were common in the American rifles, such as the Kentucky rifle. These American rifles were of a smaller caliber (typically .35 to .45 inches (8.9 to 11.4 mm)) as their primary use was hunting, while jezails had a caliber of .50 to .75 inches (13 to 19 mm) and larger, making them suitable for warfare. Having a long length, jezail was heavier (typically 12 to 14 pounds (5.4 to 6.4 kg)) than typical muskets of the time (typically 9 to 10 pounds (4.1 to 4.5 kg)). This allowed the use of larger calibers. The heavy weight of the jezail also reduced recoil. Jezail has a relatively long range of 457 metres (1,499 ft), In comparison, a Brown Bess had an effective range of 150 yards (140 m) and accurate range of 50 yards (46 m). According to some British soldiers, jezail fired a ball three times larger than that of a musket ball, with accurate range of 400 yards (370 m).

The main weakness of jezail was low rate of fire: it fired one shot each two or three minutes, in comparison to two or three shot per minute by a musket. This made it unsuitable during offensive action, while a deadly weapon as a sniper weapon in the mountains, as well as against advancing forces in open battlefield. In an attack, a soldier carried two or three jezails on his horse and after shooting with them, would return to a safe distance to reload, or proceed with hand-to-hand combat.

Although jezails were mostly smoothbore weapons, some had their barrels rifled, which, combined with the barrel's long length, made it a very accurate weapon for its time.

The lock and trigger mechanism was either a matchlock or a flintlock. Due to the complexity of the latter and difficulty of manufacture, many jezails used the lock mechanism from captured or broken Brown Bess muskets.

A unique feature of the jezail was the handmade stock, which had a distinctive curve and was intricately decorated. The role of the curve is debated. It may have made the stock lighter while still being able to be fired from the shoulder safely. It also allows firing by grasping the weapon near the trigger, like a pistol, while the curved portion is tucked under the forearm (as opposed to being held to the shoulder), allowing firing with one hand while mounted. In this case the flash pan is dangerously too close to the face and the aiming would also be more difficult, therefore this method was probably used only while mounted. The weapon could otherwise be fired from a forked A-shaped rest (which is common in Central Asia), a horn, or a metal bipod, which further improved accuracy.