The Queen has presented her husband with his Australian knighthood in a ceremony at Windsor Castle.
The honour recognises the Duke of Edinburgh's contribution to Australia throughout the Queen's reign.
Australian PM Tony Abbott recommended Prince Philip when he reintroduced the honour last year, but the decision provoked widespread criticism in the Commonwealth country.
Politicians and the media said it was out-of-step with the times.
During the investiture ceremony the Queen presented Prince Philip with the insignia of a Knight of the Order of Australia.
The duke's citation said: "For three-quarters of a century, Prince Philip has served the Crown, and the wider Commonwealth.
"He has served Australia with distinction and is patron of over 800 organisations."
Australia's honours system
Australia began awarding its own honours in 1975 - the awards eventually replaced the existing British honours system.
- Anyone can nominate an Australian citizen for an award for service, excellence or achievement
- The awarding of knighthoods and damehoods was discontinued in 1976 but brought back very briefly in 1986 - Tony Abbott reinstated them in 2014
- Only Queen Elizabeth II can appoint Australian knights and dames, on the recommendation of the prime minister
- Republicans say the honours system is an outdated remnant of colonialism
Mr Abbott's announcement on Australia Day last year that the duke would be awarded his nation's highest award prompted questions over the wisdom of knighting a British royal on a day meant to commemorate their countrymen.
The most stinging criticism came from within the conservative government's ranks, with some MPs questioning the political judgement of Australia's premier and whether he should retain the leadership of the nation.
In the wake of the controversy Mr Abbott promised to consult more widely in future.
The accolade is just one of dozens of awards received by Prince Philip, who is already a Knight of the Order of the Elephant in Denmark, a Royal Chief of the Order of Logohu in Papua New Guinea, and a Knight Grand Cross of the Order of the Netherlands Lion.