.43 Spanish

The .43 Spanish was a centerfire firearms cartridge. The .43 Spanish was adopted about 1867, and was used in early rolling block rifles that Remington manufactured for the government of Spain. The cartridge is also referred to as "11mm Spanish", and identical cartridges for the US Peabody rifle were marked "U.M.C. 43-77".

In 1869 the Spanish government put in an order for 10,000 rifles in this chambering. The Spanish military version of the cartridge was later upgraded in 1889 to a "heavier, brass-jacketed reformado bullet".