The ship will be constructed at HII's Ingalls Operations in Pascagoula, Miss., and will be delivered in fiscal year 2018.
The contract to design and build the Tripoli (LHA 7) is worth nearly $2.4 billion.
"I'm very proud of our Navy-Industry shipbuilding team and the tremendous effort that has culminated in the award of this critical shipbuilding program," said Secretary of the Navy Ray Mabus. "This ship will ensure that the amphibious fleet remains capable of expeditionary warfare well into the 21st century."
The LHA 7 will feature an enlarged hangar deck and realigned and expanded aviation maintenance facilities. The maintenance-intensive steam propulsion plants of earlier LHAs will be replaced with a gas turbine propulsion plant, zonal electrical distribution and electric auxiliary systems.
"LHA 7 will provide a flexible, multi-mission platform with capabilities that span the range of military operations -- from forward deployed crisis response to forcible entry operations," the Navy said.