How do you address Prince Phillip?

Answer 1

If you're speaking to him, the proper form is considered to be to initially address him as "Your Royal Highness" and thereafter as "sir".

If you're asking what his full official title is:

His Royal Highness The Prince Philip, Duke of Edinburgh, Earl of Merioneth, Baron Greenwich, Royal Knight of the Most Noble Order of the Garter, Knight of the Most Ancient and Most Noble Order of the Thistle, Grand Master and First and Principal Knight Grand Cross of the Order of the British Empire, Member of the Order of Merit, Companion of the Order of Australia, Extra Companion of the Queen's Service Order, Royal Chief of the Order of Logohu, Canadian Forces Decoration, Lord of Her Majesty's Most Honourable Privy Council, Privy Councillor of the Queen's Privy Council for Canada, Personal Aide-de-Camp to Her Majesty.

He's also a Field Marshal.

Answer 2

first is .. YOUR ROYAL HIGHNESS........... then after ..........SIR