Álvaro de Bazán class frigate

The Álvaro de Bazán class (also known as the F100 class of frigates) are a new class of Aegis combat system-equipped air defence frigates entering service with the Spanish Navy. They are being built in the Spanish factory of Navantia in Ferrol and are named after Admiral Álvaro de Bazán.

The ships are fitted with American Aegis weapons technology allowing them to track hundreds of airborne targets simultaneously as part of its air defence network. The F100 Álvaro de Bazán-class multi-role frigate is one of the few non-US warships to carry the Aegis Combat System and its associated AN/SPY-1 radar. Japan's Kongō class, South Korea's Sejong the Great class, the F100-derived Norwegian Fridtjof Nansen class of frigates also use the Aegis system. Lockheed Martin, Navantia and the U.S. Navy are conducting final systems integration.

The F105 will be the basis of the Australian Hobart-class destroyer (previously known as the "Air Warfare Destroyer"). The Australian government announced in June 2007 that, in partnership with Navantia, three F100 vessels will be built for the Royal Australian Navy (RAN) with the first due for delivery in 2014.

The Australian Government also confirmed in April 2016 that a modified F100 class was one of three vessels shortlisted to replace the Anzac-class frigates currently in service with the RAN.

The Álvaro de Bazán-class frigates are the first modern vessels of the Spanish Navy to incorporate ballistic resistant steel in the hull, along with the power plants being mounted on anti-vibration mounts to reduce noise and make them less detectable by submarines. The original contract for four ships was worth €1,683m but they ended up costing €1,810m. As of 2010 it was estimated that the final vessel, F-105 would cost €834m (~US$1.1bn).