Ceremonies across the country commemorated those who lost their lives in two world wars and subsequent conflicts.
In shopping centres, schools and workplaces, and at cenotaphs, people fell silent, in line with tradition, at 11am, marking the moment guns stopped firing at the end of the First World War.
In Afghanistan, British defence secretary Philip Hammond joined 3,500 troops at a special parade in Camp Bastion.
The death of a British soldier in Helmand this week brought to 385 the number of British fatalities in Afghanistan since the conflict began in 2001.
“The ceremonies that we will have across Britain on Remembrance Sunday are not just about the war dead from the First and Second World Wars, or even conflicts we’ve had since, but this is about an ongoing sacrifice that people here are making on a daily, weekly basis that they all live with every day,” he said.
Prime Minister David Cameron paid tribute to British troops in a message on the Downing Street website, which was played at the Royal British Legion event in Trafalgar Square.
“We stand together to honour the incredible courage and sacrifice of generations of British service men and women who have given their lives to protect the freedoms that we enjoy today,” he said.
“From the trenches of the First World War to the desert of Afghanistan our armed forces have proved time and again that they are the bravest of the brave and the very best of what it means to be British. We can never fully repay the debt we owe them.”
Nearly 200 members of the far-right English Defence League were arrested for public order offences at memorial events in central London.