The Invincible-class were an innovative design for a light carrier capable of carrying helicopters as well as the Sea Harrier vertical take-off aircraft. It was originally conceived following the cancellation of the CVA-01 fleet carrier concept and the 1966 decision to scrap the UK's carrier force (which by 1972 left the country with no fleet carriers for the first time since 1918). Political considerations resulted in the Invincible ships being designated as "thorough-deck cruisers" although they were carriers in all but name. A novel ski-jump was installed on the port side which allowed the Harriers a short take-off with a heavier weapons load; provision was originally for nine Sea King helicopters and five Sea Harriers but ultimately they could be fitted with as many as 22 total aircraft. Defensive armament included Sea Dart SAMSs as well as either Phalanx or Goalkeeper CIWS added lighter. At the time, the Invincible-class carriers were the largest ships equipped with a gas turbine and the ship layout allowed most machinery to be removable for ease of maintenance. It was most fortunate that the UK was able to count on one of these ships for the Falklands campaign in 1982 where the Sea Harriers proved invaluable for combat air support (attached RAF Harrier GR3s were also used for ground attack). For the remainder of the Cold War they served as flagships for anti-submarine task forces along the Greenland-Iceland-UK gap but later participated in numerous other post-Cold War conflicts including the Gulf War, the conflicts in Yugoslavia, and the wars in Iraq and Afghanistan. In anticipation of the upcoming Queen Elizabeth-class nuclear carriers, the three Invincible-class ships were gradually phased out of service, the last in 2014. Perhaps their greatest legacy was serving as a template for nearly every other modern light carrier (or "Harrier carrier") built since, and which have allowed smaller navies the ability to project power on a budget.

The lead ship, HMS Invincible was the only one of the class ready for the onset of hostilities in the South Atlantic in 1982 where along with HMS Hermes formed the backbone of the Royal Navy task force sent to recapture the Falklands. It was later used in both the Yugoslavia and Kosovo campaigns as well as in the Iraq War. The HMS Illustrious relieved its sister in the South Atlantic after the end of the Falklands War. It would also be deployed in the Balkans as well as for various operations over Iraq during the 1990s. The HMS Ark Royal would also serve in some of these same conflicts (including the Iraq War), and was notable for its use as a helicopter landing platform while HMS Ocean was in refit.