The West Wales region have wasted no time in snapping up Marshall, who will join an already strong foreign contingent playing their rugby at Liberty Stadium. Marshall said: "I was approached by clubs from England and France but I have been motivated by the region's ambitions, once I had spoken to the Ospreys and seen the area and set up with my own eyes, it was a simple decision in the end.
"The Ospreys are a team that are going places and I have been very impressed with their professionalism on and off the pitch. They have a magnificent stadium, some of the best training facilities I've seen and a squad that I believe can compete with the best in Europe. I am a very ambitious, competitive individual and I look forward to furthering my ambitions with the Ospreys."
Ospreys Regional Rugby Manager, Derwyn Jones was clearly delighted with his new aquisition.
"We are carefully targetting key players, but we will only confirm signings as and when the time is right for us," said Jones. "There is a tremendous team spirit within the squad and we are mindful not to disrupt the progress we have made over recent months. However, with the massive media interest that signing a player of Justins stature naturally brings, this announcement is unavoidable.
"There was significant interest in securing Justins services from top European sides, and it speaks volumes for us that he will be wearing an Ospreys shirt next season. Further signings will be confirmed as and when appropriate over the next few months."