Britain's oldest war veteran was taking part in the march past the Cenotaph in London on Remembrance Sunday.
Mr Allingham was in France to lay a wreath on Armistice Day
Henry Allingham, 109, from Eastbourne, East Sussex, was a WWI aircraft engineer and is the last survivor from the Royal Air Force's creation in 1918.
He was in France for Armistice Day on Friday where he laid wreaths at memorials in St Omer, near Calais, in honour of his fallen comrades.
Mr Allingham served in the British airbase there during 1917.
St Omer is now the location of the first permanent memorial to the 4,700 British air personnel who died while fighting on the Western Front.
Sea cadet parade
Before the ceremony, the last survivor of the Battle of Jutland said: "I feel great respect for the men I know who have given so much on my behalf, and yours, in service of our country."
Cities, towns and villages across the South East were joining the rest of the country to mark Remembrance Day.
Sea cadets who took part in Trafalgar Day celebrations led a parade through the centre of Tunbridge Wells, Kent.
Mr Allingham lit a candle at a church in St Omer, near Calais
School children in Crowborough, East Sussex, were taking part in an oral history project by interviewing people who lived through World War II for the BBC's People's War project.
The firing of maroons took place at the Port of Ramsgate, and ceremonies were planned at war memorials in towns including Woking in Surrey, Worthing in West Sussex and Dover in Kent.
And in Guildford, members of the Peace Party and other organisations gathered in the castle grounds to lay a wreath of white poppies, the alternative symbol adopted by the peace movement.
In Dover, town clerk Mike Webb said there would a robed ceremony followed by a memorial service at St Mary's Church which everybody was welcome to attend.