The P-900 Alfa (or also P-900A Alfa) П-900 3М51 Альфа Alfa AFM-L, GRAU designation 3M51, is an anti-ship missile (with LACM capabilities) developed from the 3M54 Kalibr, P-800 Oniks and P-700 Granit.

The missile has a Granit type engine. It can be operated on new Yasen-class submarine, and can be loaded on ships.^{[citation needed]} Coastal versions of the anti-ship missile are under development.^[1] The missile is developed at NPO Mashinostroyeniya.^[1]

3M-51 Alfa is also designated as Novator KTRV, Morinform Agat, 3M54, 3M54E and P-900 types.^{[citation needed]}

The new cruise missile was designed for use in the Russian Navy.^[1] Modernization of Kirov-class battlecruiser, other new battlecruisers, destroyers and cruisers may include 3M-51 Alfa that can be refitted on ships with existing Zircon, Grom Meteorit, GELA, P1200 Bolid or P-1000 Vulkan missile launchers.^{[citation needed]}

Despite a secrecy surrounding the new missile, it can be presumed that it holds promise as an exportable weapons system.^[1]

• Yasen-class submarine – (Russia)
• Qader – (Iran)
• Storm Shadow – (France, United Kingdom)
• Atmaca – (Turkey)
• Babur – (Pakistan)
• SOM – (Turkey)
• Noor ASCM – (Iran)
• Zafar – (Iran)
• Khalij Fars – (Iran)
• 3M-54 Klub – (Russia)
• BrahMos – (Russia, India)
• BrahMos-II – (India, Russia)
• Kh-90 – (Russia)
• Future Cruise/Anti-Ship Weapon – (France, Italy, United Kingdom)

• AFM-L Alfa (Federation of American Scientists)
• 3M51 Alfa (Missile Threat)