SSGN is the United States Navy hull classification symbol for a cruise missile submarine. The SS denotes a submarine, the G denotes "guided missile," and the N denotes nuclear power.

The US Navy is modifiying surplus Ohio class Trident submarines to SSGN configuration. This is achieved by the installation of vertical launch systems (VLS). If the maximum of 154 Tomahawk missiles were loaded, one Ohio-class SSGN would carry an entire Battle Group's equivalent of cruise missiles.

The first SSGN in the USN was the USS Halibut (SSGN-587)

See also

• SSG
• SSN
• SSBN