USS Green Bay (LPD 20), a San Antonio-class amphibious transport dock, is the second ship of the United States Navy to be named for the city in Wisconsin.

The contract to build her was awarded to Northrop Grumman Ship Systems, Avondale Division of New Orleans, Louisiana, on May 30, 2000, and her keel was laid down on August 11, 2003. Green Bay was christened on July 15, 2006. Rose Magnus, wife of the assistant commandant of the Marine Corps, General Robert Magnus, served as the ship’s sponsor. PCU Green Bay is scheduled to be commissioned in 2008 and be assigned to the Atlantic Fleet. Cmdr. Calvin Slocumb is the ship's prospective commanding officer.

August 6, 2008 PCU Green Bay, commanded by Cmdr. Joseph R. Olson, completed Acceptance Trials on Aug. 1, sailing from and returning to the Northrop Grumman Shipbuilding (NGSB) shipyard in New Orleans.

September 5, U.S. Navy accepted delivery of the Green Bay from Northrop Grumman Shipbuilding (NGSB) in New Orleans, La., Aug. 29.

December 17, LPD 20 arrived in its new homeport of San Diego for the first time.

January 24, 2009 USS Green Bay is commissioned during a 10 a.m. ceremony in Long Beach, Calif.

September 23, The amphibious transport dock pulled to Pearl Harbor Naval Station for a routine port visit.

September 29, The Green Bay is currently conducting Combat System Ship Qualification Trials (CSSQT) off the coast of Hawaii.

October 10, USS Green Bay arrived in San Francisco to participate in Fleet Week 2009.