Swansea born Evans, 25, put pen to paper on a three-year contract at the start of January and will make the switch to the Liberty Stadium in the summer.
Having been a talented schoolboy athlete and national hurdles champion, Evans made 74 appearances for the Scarlets (83pts/10 tries) before moving to Newport Gwent Dragons in 2012. He has been arguably the most consistent player at Rodney Parade over the last two seasons, scoring 11 tries and 64 points in his 42 appearances to date, with one of his tries coming against the Ospreys at the Liberty Stadium 10 months ago.
His two Wales caps came on the 2009 tour to North America, where he started in the wins over Canada and USA.
Evans says that he is looking forward to joining up with his new team-mates for 2014/15.
"This is a great opportunity for me" he said.
"The Ospreys have been the most successful team in Wales over the last 10 years, winning leagues and producing players for the national team. There is some real world class talent in the squad so it's a big challenge for me personally, but I can't wait to get involved and fight for my place. I want to be a part of a successful Ospreys team."
"There are a lot of good players here, not only the senior ones, but a lot of good youngsters coming through. There's a good blend which is what is needed in a successful side. I've got a lot of experience now, not only in the Rabo but in Europe as well, but I've still got a lot to learn. The coaches have said they've seen something they like in me and they believe I can do a job for the Ospreys, and I'm excited about this opportunity. Hopefully being in this environment with international players and quality coaches will improve my game and help me become a better player."
Andy Lloyd, Rugby Operations Manager at the Ospreys, welcomed Evans to the Liberty Stadium, saying:
"We are delighted to have been able to secure the services of a talented Welsh player who has been in eye-catching form over the last two seasons. It's great news for the region that he wanted to come here."
"He's a player that Gruff Rees knows very well having coached him at age-grade level in his role as a WRU Skills Coach, and Gruff is excited about working with him once again, this time as part of the Ospreys."
"Dan is someone who has always displayed real talent but the last couple of years, with a consistent run of games, have really seen him flourish and he is performing week in, week out at a high level. He's got a great left foot which everybody can see, but also, his physical attributes and his understanding and decision making at the back are particular assets."
"We believe that Dan is a good fit for us, the way that our back line is developing around a group of players who may be young in age but are gaining a lot of experience and are starting to mature as a collective. He's been a regular points scorer over the last few years and while we believe that we can help him reach that next level, he can also give us some focus at the back and create some real competition for the shirt."
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