The IZh-43 (ИЖ-43) is a Soviet and Russian double-barreled shotgun.

The IZh-43 was designed in the early 1980s, and in October 1985, the first prototypes were presented at the hunting weapons exhibition in Irkutsk. Production of these weapons began in 1986.

In 1986, the IZh-43M shotgun was awarded the gold medal at the Leipzig Trade Fair.

From July 1987 until February 1990, the price of a standard IZh-43 was 175 rubles. A custom IZh-43 shotgun, featuring engravings, a walnut stock, and a walnut fore-end, was priced at up to 385 rubles.

In 1988, the Izhevsk Mechanical Plant began mass production of both the IZh-43 and IZh-43E.

In January 2004, a contract was signed between Remington Arms and the Izhevsk Mechanical Plant. Russian firearms were bought by Remington and sold in the USA, with the IZh-43 being marketed as the Remington Spartan 220 and the IZh-43-1S as the Remington Spartan 210.

In September 2008, all firearms produced by the Izhevsk Mechanical Plant were rebranded, and the IZh-43 was renamed the MP-43 (Mechanical Plant-43).

The IZh-43 is a side-by-side smoothbore shotgun, with barrels that feature chokes at the muzzle end.