Organised by the Royal British Legion, it featured a service of remembrance and a wreath-laying ceremony at the Armed Forces Memorial.
The 235 guests included the serving and veteran communities of Afghanistan, the families of those who served, and those who worked as civilian contractors supporting UK forces and civil society during the conflict.
Defence Secretary John Healey laying a wreath at the Iraq and Afghanistan Memorial in London, to mark 10 years since the end of UK combat operations in Afghanistan (Sgt Jimmy Wise/UK MOD Crown Copyright/PA)
Minister for veterans and people Alistair Carns, who is a veteran of the conflict himself, attended the ceremony and laid a wreath.
Victoria Bateman, widow of Lance Corporal James Bateman who in 2008 became the 101st British soldier to be killed in Afghanistan, gave a reading.
Earlier in the week, Defence Secretary John Healey laid a wreath at the Iraq and Afghanistan Memorial at the Ministry of Defence in London.
October 26 marks 10 years since UK forces ended combat operations in Helmand, Afghanistan, and handed over Camp Bastion to the Afghan authorities.
Some 150,000 British armed forces personnel served in Afghanistan and 457 died.
Mr Healey said: “As we mark a decade since the conclusion of UK combat operations in Afghanistan, we honour the immense sacrifice made by our personnel.
“We remember the 457 British personnel who lost their lives, the thousands who were wounded, and the families who bore such a burden during this conflict.”
Mr Carns said: “The 10-year anniversary of the end of UK combat operations in Afghanistan is a solemn occasion for reflection.
“Having served five operational tours in Afghanistan, it was a deeply personal moment to lay a wreath for those who served and died.
“We remain committed to supporting the Afghan people through diplomatic and humanitarian efforts.”
Chief of the Defence Staff Admiral Sir Tony Radakin said: “Today, we remember the bravery and sacrifice of our armed forces personnel who served in Afghanistan.
“A decade on from the end of UK combat operations, we remain committed to honouring the 150,000 personnel who served and the 457 men and women who made the ultimate sacrifice.”
The Royal British Legion’s director of remembrance Philippa Rawlinson said: “Many families lost loved ones during Operation Herrick, and as we mark 10 years since the end of combat operations in Afghanistan, we remember those who made the ultimate sacrifice and the RBL stands ready to support those in our community impacted by this conflict.
“In a year when we’re marking significant 80th Second World War anniversaries, it’s important we also take time to remember the service and sacrifices of more recent conflict and the younger generation of the armed forces community, including those who fought in Afghanistan.”
UK military involvement in Afghanistan began in October 2001 as part of the Nato response to the 9/11 attacks.