The 28-year old Fussell has followed on from Tom Grabham, Tom Isaacs, Duncan Jones, Rhys Webb, Joe Bearman, Lloyd Peers and James King to re-sign for the Ospreys, putting pen to paper on a contract that will keep him at the Liberty Stadium until the end of the 2015/16 season.
"This is great news for the Ospreys," said Andy Lloyd, Rugby Operations Manager at the Ospreys.
"If I'm honest, I believe that Richard is someone who goes under the radar outside of our environment but he is a model of consistency for us and has been outstanding ever since he arrived at the Ospreys.
"This season in particular he's been sensational, the way he's coped with being the old head and the only constant in an ever changing, regularly patched up back three. He's dealt magnificently with having to work with so many different combinations and his attitude in helping through so many youngsters has been admirable. It's summed up perfectly what he brings to this squad."
Fussell signed for the Ospreys in the summer of 2010, arriving at the Liberty Stadium with a reputation as a try-scoring winger having touched down 23 times in 78 appearances for Newport Gwent Dragons. He scored a try on his Ospreys debut, a defeat to Ulster on the opening day of the 2010/11 season and finished the season as the region's top try scorer with nine.
Since then he has successfully been converted to full back, growing ever more influential in the Ospreys shirt, and made his 77th appearance for the region in Friday night's PRO12 clash against the Dragons at the Liberty.
"It's huge for me, knowing that the Ospreys want to keep me here for the long term. It's great to know that management see me as part of the future of the region," said Fussell.
"I really enjoy being part of the squad. There's been a bit of a change for me over the last couple of seasons, I've played wing since I was a youngster playing age-grade rugby but moving to the Ospreys and then switching to full back has given me a new lease of life, a new direction. It's opened my eyes a little bit and I'm grateful to have been given the opportunity here.
"The first goal over the three years of the new contract is to keep that jersey. We want to push on as a team over the rest of the season, try and get into the play-offs and retain the PRO12 trophy, while on a personal level I want to keep pushing myself and continue improving."