A graduate of the regional development pathway at the Ospreys, the 27-year old prop made his debut at the end of the 2007/08 season, away to Connacht, and became only the 25th Ospreys centurion in a 26-12 win over Munster at the Liberty Stadium in March of last year.
Capped 13 times by Wales, he made a total of 112 Ospreys appearances, scoring three tries, but has found game-time limited over the last two seasons due to injury.
Bevington said: “It’s a sad moment for me to be moving on from my home region, where I have been involved since I was 15 years old, but I believe that this is an exciting opportunity for me to try and get back to the level that I know I can play.
“I have enjoyed every minute of my time as an Osprey, playing alongside some of the best players Wales has to offer and winning the league twice, in 2010 and 2012.
“It’s clear that the Ospreys have a bright future ahead with such a young team coming through and I’ll continue to be behind the boys from distance.
“The next chapter of my career starts this week and I’m really looking forward to it, but I wish the Ospreys players, coaches, staff and supporters, all the best for the season and thank you for the great memories.”
Head Coach, Steve Tandy, wished Bevington all the best, saying: “Ryan has been a good servant to the region, making over 100 appearances and giving everything, every time he wore the jersey. Unfortunately, he has had some injury problems in recent years and the nature of professional sport is such that one player’s misfortune can be another’s opportunity and he has found his chances limited.
“He’s worked hard to get back to full fitness, maintaining the levels of professionalism required of an Osprey, but, understandably, he feels that the best option for him at this stage of his career is a fresh challenge in a new environment and we wish him the very best at Bristol.”