Having developed a reputation as a quality finisher, Fussell joins the Ospreys from Newport Gwent Dragons where he is out of contract at the end of the current season, having made 78 appearances since arriving at Rodney Parade in 2005, scoring 23 tries.
Standing 1.8m tall and weighing in at 87kg, Fussell has been capped by Wales at all the age-grade levels. Prior to joining the Dragons, he played 46 times for Pontypridd, scoring 21 tries.
Sean Holley, Ospreys Head Coach, said: "Clearly, with Shane Williams, Tommy Bowe, Nikki Walker and now Kristian Phillips and Tom Prydie all getting called up for international rugby at different stages of the season, we felt that we needed to add strength to our wing department to cover for these players. We also see Tom Prydie as someone who in the longer term will emerge as a full-back, so we were in no doubt about the need to bring someone in.
"We were looking for someone who was Welsh, who was a consistent player, and in Richard, we saw somebody who has hit some good form, understands a sound defensive system, has the ability to kick off his left foot and has become a proven finisher. He has all the attributes that we look for in a winger at the Ospreys.
"He was coming out of contract and both parties expressed an interest to come together. As a coaching team, all we can do is review the footage and make the recommendations. In Richard's case, we recommended that he was a player that could be a real asset to the Ospreys, and I'm looking forward to working with him next season."
Elite Performance Director, Andrew Hore, added:
"We have invested heavily in facilities, personnel and coaching structures, and the set-up we have here is proving an attraction to quality players who want to come here and be a part of what we are trying to build at the Ospreys. In Richard's case, we are delighted to welcome him into our environment and are looking forward to seeing him grow as a player over the coming seasons.
"He has genuine aspirations to represent Wales at senior level, and with our proven track record for player development we strongly believe that we can help him to achieve that goal."