The U.S. Navy Marine Mammal Program (NMMP) is a program administered by the U.S. Navy which studies the military use of marine mammals - principally bottlenose dolphins and California sea lions - and trains animals to perform tasks such as ship and harbor protection, mine detection and clearance, and equipment recovery. The program is based in San Diego, California, where animals are housed and trained on an ongoing basis. NMMP animal teams have been deployed for use in combat zones, such as during the Vietnam War and the Iraq War.

The program has been dogged by controversy over the treatment of the animals and speculation as to the nature of its mission and training. This has been due at least in part to the secrecy of the program, which was de-classified in the early 1990s. Since the program's inception, there have been ongoing animal welfare concerns, with many opposing the use of marine mammals in military applications, even in essentially non-combatant roles such as mine detection. The Navy cites external oversight, including ongoing monitoring, in defense of its animal care standards.