Lance Corporal Jonathan McKinlay, of Gloucestershire-based 1st Battalion The Rifles, was killed by small arms fire on Wednesday.
L/Cpl McKinlay, 33, from Darlington, was based at Check Point Chaabak in the Nahr-e-Saraj South district of Helmand.
A total of 381 British troops have been killed in Afghanistan since military operations began in 2001.
L/Cpl McKinlay had been on patrol in a village with his team and members of the Afghan police when he was killed.
The Ministry of Defence (MoD) said he deployed to Afghanistan in June.
Commanding officer Lt Col James de Labilliere said: "To anyone who met him, Lance Corporal Jon McKinlay made an instant impression.
"On the one hand a hard professional soldier who demanded the very highest standards from himself and his men and yet on the other a man of great compassion, humour and somebody who had time for others.
"He had irrepressible energy and was industrious to the core."
L/Cpl McKinlay was married with one daughter and two step-children.
His wife Lisa said: "He was a true friend to others and a loving husband, a real joker and my one in a million."
L/Cpl McKinlay joined the Army in 1996 and had previously been deployed to Northern Ireland, Iraq and Afghanistan.
Defence Secretary Liam Fox said: "I was very saddened to learn of the death of Lance Corporal Jonathan McKinlay whilst serving in Afghanistan.
"Throughout the 15 years he served in the Army he showed great professionalism and commitment."
A British soldier who was shot dead while on patrol in Afghanistan has been named by the Ministry of Defence.