The designation Mark 46 can refer to:
- Mark 46 machine gun, lighter weight version of the M249 machine gun
- Mk 46 nuclear bomb
- Mark 46 torpedoMark 46 torpedoDesigned to attack high-performance submarines, the Mark 46 torpedo is the backbone of the U.S. Navy's lightweight ASW torpedo inventory, and is the current NATO standard. These aerial torpedoes, such as the Mark 46 Mod 5, are expected to remain in service until the year 2015...