The nation fell silent to honour those who died in war.
A two-minute silence took place across the country at 11am.
It is now 100 years since the first two-minute silence was observed on Armistice Day, November 11 1919.
Prime Minister Boris Johnson laid a wreath and spoke to a veteran during a service at the cenotaph in St Peter’s Square, Wolverhampton.
Labour Party leader Jeremy Corbyn and shadow foreign secretary Emily Thornberry attended a service outside Islington Town Hall, north London.
Brexit Party leader Nigel Farage was among those who marked the occasion at Hartlepool War Memorial.
The Royal British Legion asked that people pause by muting their telephones, closing laptops, switching off television sets “for just two minutes and pay your respects to our Armed Forces community, past and present”.
It is a time to honour those “who serve to defend our freedoms and way of life”, said the RBL.
They said the sacrifice of the Armed Forces community from Britain and the Commonwealth are brought to mind while the innocent civilians who have lost their lives in conflict and acts of terrorism are also not forgotten.
It also serves as a tribute to the special contribution of families and of the emergency services.
The Duke of Kent led tributes at the National Memorial Arboretum (NMA) in Staffordshire which was created to honour more than 16,000 servicemen and women who have been killed since 1948 while on duty or because of terrorist action.
NMA managing director Philippa Rawlinson said: “Across the country, people have gathered to remember those who have made the ultimate sacrifice for our freedom and way of life.
“It is essential that we continue to observe this important day and preserve the memory of those who have fallen whilst serving our nation.”