The first of a revolutionary of a new class of fast attack submarines, the Seawolf, was christened June 24, 1995, at the Electric Boat Division of General Dynamics Corporation in Groton, Conn. SSN 21 was commissioned during a ceremony on July 19, 1997, at Electric Boat Shipyard, with Cmdr. David M. McCall in command. She is the first "top to bottom" new attack submarine design since the Skipjack-class in the early 1960s.

After a period of post-construction testing, additional modifications, and depot level repairs, USS Seawolf, commanded by Cmdr. Butch Howard, departed in June 2001 for its maiden deployment. The terrorist attacks of Sept. 11 forced an early underway from a planned upkeep in Faslane, Scotland, and accelerated the submarine's passage through the Straits of Gibraltar into the Mediterranean Sea. The ship sortied from Scotland, moved halfway back to the East Coast to await the arrival of the USS Theodore Roosevelt (CVN 71) Battle Group, and earned a certification to conduct strike operations. Soon after, urgent orders sent the submarine directly to the Mediterranean to increase the number of Tomahawks and launch platforms in the theater of operations. As the Seawolf waited for potential orders for Operation Enduring Freedom, while additionally providing support to the TR BG, she played a role in her first NATO exercise, Destined Glory 2001. Later she met up for the first time with the submarine tender USS Emory S. Land (AS 39) in La Maddalena, Italy, to trade some of the submarine's torpedo payload for cruise missiles, take on another 60 days' worth of food, and conduct minor voyage repairs. SSN 21 returned to Naval Submarine Base New London in December after traveling 33,200 miles.

On October 30, 2002, USS Seawolf returned to Electric Boat for a three-week repair period, the second time a U.S. Navy submarine had docked at the shipyard under the terms of a leasing agreement announced earlier in 2002. Although the ship will be docked at EB, the repair job will actually be managed by the Naval Submarine Support Facility at the sub base.

May 27, 2003 USS Seawolf, commanded by Cmdr. Paul T. Stevens, departed Groton, Conn., for a scheduled six-month deployment in the Atlantic Ocean and European Theater.

August 27, SSN 21 is currently participating in Anti-Submarine Warfare (ASW) exercise Odin-One in the North Sea region.

October 19, 2006 The nuclear-powered attack submarine pulled into Apra Harbor for its first port visit to the island of Guam.

July 22, 2007 USS Seawolf arrived at its new homeport of Naval Base Kitsap-Bremerton in Bremerton, Wash., after a 37-day transit from Groton, Conn.

February 12, 2009 SSN 21 completed its participation in undersea warfare exercise with USS John C. Stennis (CVN 74) CSG, Japan Maritime Self-Defense Force and five other U.S. combat ships currently operating in the 7th Fleet area of responsibility.

May 9, The Seawolf arrived in Fleet Activities Yokosuka, Japan, for a five-day port call after participated in exercise Malabar 2009, off the coast of Okinawa.

June 3, USS Seawolf returned to Bremerton after a six-month deployment.

February 17, 2010 Cmdr. Daniel Packer relieved Cmdr. Harry Ganteaume as CO of the Seawolf during a change-of-command ceremony at Naval Base Kitsap.

April 3, 2012 USS Seawolf returned to Naval Base Kitsap-Bremerton after sea trials, completing the 31-month, $280 million worth, Depot Modernization Period (DMP) at the Puget Sound Naval Shipyard and Intermediate Maintenance Facility (PSNS&IMF).

July 23, 2013 USS Seawolf departed homeport for a scheduled deployment.

September 11, SSN 21 recently moored at Haakonsvern Naval Base in Bergen, Norway, for a routine port call.

January 21, 2014 USS Seawolf returned to Bremerton after a six-month North Atlantic deployment.

February 5, Cmdr Jeffrey M. Bierley relieved Capt. Broderick V. Berkhout as commanding officer of the Seawolf. Capt. Berkhout was the CO since March 2013.

February 6, Cmdr Bierley relieved of duty Master Chief Electronics Technician (SS) Mark R. Philiposian as USS Seawolf's Chief of the Boat, due to "unsatisfactory performance."

July 28, USS Seawolf arrived in Naval Base Point Loma in San Diego, Calif., for a brief port call to embark midshipmen for annual summer training.