The 32-year old left Saints to take up a two-year deal with Hull KR at the end of last season but has now re-joined his former club for just the 2010 season.
He spent four years with St Helens and made his only Great Britain appearance during that time.
Coach Mick Potter feels that bringing back Fozzard was a necessary action for the Knowsley Road side as they struggled at times in the forwards.
“We’ve definitely suffered from not having one of our front line props for the whole of this season due to Jason Cayless injury and Nick Fozzard will help fill that role well for us next season,” he said.
Fozzard is also pleased to back playing in the red vee of Saints.
“I would like to thank Morgs [Justin Morgan] and the boys for helping me fit in so quickly and I’d especially like to thank all the Red and White fans that have made me feel so welcome since arriving here.
“I’m absolutely thrilled to be back at the Saints. I had a fantastic five seasons there and it will be great to be back with my old team mates and friends. The Saints fans can expect my absolute best for them next season.”
Former coach Justin Morgan added: “I’d like to thank Nick for his contribution whilst being here at Rovers. He has done a great job for us and we wish him all the best for next season.”