The Royal Marine was wounded as a result of an explosion that occcurred while he was travelling in a Viking vehicle near Lashkar Gah in Helmand province on the morning of 22 May 2009.
He received immediate medical attention both on the ground and at an ISAF (International Security Assistance Force) medical facility, prior to being returned to the UK for further specialist treatment.
Spokesman for Task Force Helmand, Lieutenant Colonel Nick Richardson, said:
"It is with extreme sadness that I must report the death of a brave Marine. He laid down his life for his country and the good people of Afghanistan. We grieve for his loss and join with his family and friends to mourn his passing."
Next of kin have been informed and have asked for a period of grace before further details are released.