The soldier was on a foot patrol when the explosion took place
A British soldier from 3rd Battalion The Rifles died in an explosion in southern Afghanistan, the Ministry of Defence said.
The soldier died on Sunday and his family has been informed.
He was killed as a result of an explosion that happened near Forward Operating Base Zeebrugge, in the Kajaki area of Helmand Province.
The number of British military personnel killed on operations in Afghanistan since 2001 is now 280.
Spokesman for Task Force Helmand, Lieutenant Colonel David Wakefield, said the soldier was on a foot patrol against insurgents when the explosion happened.
"His courage and resolve, confronting the enemy and the dangers of IEDs day on day, will not be forgotten. We will remember him," he added.
The previous UK soldier to die in Afghanistan was Guardsman Michael Sweeney, 19, of 1st Battalion Coldstream Guards, who was killed in the Babaji district of central Helmand province on Thursday morning.