Scotland's First Minister Nicola Sturgeon said: "Our thoughts are with the Royal Family at this difficult time and their grief is shared by people across the country."
The First Minister of Wales, Mark Drakeford, said: “Prince Philip would be sorely missed by the people of Wales".
"Throughout his long and distinguished life, he served the crown with selfless devotion and generosity of spirit," he added.
Northern Ireland's First Minister Arlene Foster also offered her "deepest sympathies" to the Queen and the Royal Family "at this sad time".
The Scottish Tories, Scottish Labour, Scottish Liberal Democrats and the SNP also confirmed they will pause campaigning following the news.
Labour Mayor of London Sadiq Khan paid tribute to the Duke’s contributions to the capital this afternoon, saying: “Prince Philip had a positive impact on London, Britain and the lives of so many will live on for many years to come.
“I extend my deepest sympathies to Her Majesty The Queen and the entire Royal Family at this sad time.”
Flags will fly at half-mast on UK Government buildings in tribute to the Duke of Edinburgh until the morning after his funeral.