Standing 6'5" and weighing 115kgs, Guy is an imposing figure on the rugby field and his size and strength has seen him as a threat in both attack and defence. He has played 12 times for Irish this season to add to his total of 21 appearances.
London Irish Director of Rugby Brian Smith said: "Guy Armitage is fast becoming one of the most dynamic power centres in the country. He's a genuine Premiership player with the ability to go on and play for England like his two older brothers. Guy has forced his way into the starting team this season and if he keeps performing may well be considered for England's summer tour of Argentina."
Guy Armitage said: "I have really enjoyed my rugby since I returned to London Irish from Toulon. I have come through the ranks with a number of these players and enjoy playing with them week in week out. I look forward to pushing on as a player and with the club over the next few seasons."