As the battalion’s Colonel, he addressed 450 soldiers during a ceremony held before friends and family in the quadrangle of Windsor Castle.
The Duke said he was “immensely proud” of all the regiment had achieved since it last received new colours 13 years ago, noting that in the interim the assembled soldiers had served in Afghanistan, Cyprus, South Sudan, Kosovo and Iraq.
He said: “I am speaking to those Guardsmen, and indeed every one of you assembled here today, when I say that I am immensely proud of what you have achieved.
“The indomitable family spirit of the Micks remains your hallmark and I know that the support and devotion of the Regimental family remains as strong as ever.”
The Duke added: “I know that Her Majesty is looking forward to seeing these new colours trooped during her official birthday parade next month.”
On June 2, the 1st Battalion Irish Guards will kick off the official Platinum Jubilee celebrations as they troop the colour before the Queen, showing off their new ceremonial flag.
More than 1,200 officers and soldiers from the Household Division will put on a display of military pageantry on Horse Guards Parade, together with hundreds of Army musicians and around 240 horses.
In Windsor, the Irish Guards, along with the Band of the Irish Guards and the Corps of Drums led by regimental mascot Irish Wolfhound Turlough Mór, marched out of Victoria Barracks bearing their old colours.
They paraded through the town and into the grounds of Windsor Castle, watched by around 500 friends and family members and Ben Wallace, the Defence Secretary.
Commanding Officer Lieutenant Colonel James Armitage called the parade to attention and gave the order to present arms in a General Salute.
The old colours were marched off parade, and the Duke took up his position on the dais alongside General Sir Mark Carleton-Smith, the Chief of the General Staff, and Major Niall Hall, the Irish Guards’ Regimental Adjutant.
He stood for the Royal Salute, followed by the national anthem. Two soldiers succumbed to the heat and fainted.
The Duke, along with the Commanding Officer and the Equerry, then inspected the front rank of the Irish Guards.
After prayers and the consecration of the new colours, the Duke presented the colours and addressed the regiment.
Three cheers for the Queen then rang out, followed by three cheers for the Duke.
Following a march past, the Duke posed for a photograph with officers and warrant officers before joining a private reception to meet friends and relatives.
The Duke has been Colonel of the Irish Guards since 2011 and wore the regimental uniform during his wedding later that year.
Their red tunics have buttons arranged in groups of four to distinguish them from the other four regiments of foot guards.
New colours are traditionally presented every 10 years, but the Irish Guards’ old colours were presented by the Queen in 2009.
The delay in renewal was due partly to the pandemic and partly to the Guards’ operational commitments in recent years.