The 23-year old has penned a three-year deal, making him the 13th player to re-commit so far in 2014.
"I'm very, very happy to have another three years" said Dirksen.
"I haven't had much game time this year because of a long injury, but I'm back playing again and I just want to be on the field with the jersey as much as I can, to make up for missing so much rugby.
"There is competition for places on the wing now and you need that, to make you improve and be a better player. It's the last game of the season on Saturday so it's important I finish well, work hard over the summer and then come back for pre-season to hopefully get back to where I was before the injury.
"The region has been very good to me. It's where I've developed as a rugby player and is home for me, which makes it even more special to stay here."
Born in Krugersdorp, in the Gauteng province of South Africa, Dirksen arrived in Ospreylia as a teenager, via Tennessee, USA, and Truro, Cornwall.
His family moved to the USA in 2006, where he represented the Eagles at age-grade level, and played in an uncapped match for the senior team against Munster in the summer of 2008.
Having studied at Truro College in 2008/09 - where he played in the centre alongside the Ospreys' summer signing Josh Matavesi, with both players scoring in a try in Truro's victory in the Daily Mail RBS Schools Cup Final at Twickenham - he moved to Neath Port Talbot College the following year. Based in Ospreylia, he made a huge impression in the Premiership with Swansea, scoring 21 tries in 22 games and claiming the Young Player of the Year award for the All Whites for 2009/10.
He made his Ospreys debut as a teenager in a LV= Cup defeat in November 2009. His only other appearance that season, against Leeds at the Liberty Stadium, saw him mark his first start with his first try.
Armed with his first pro contract, signed at the start of 2011, Dirksen established himself in the senior squad during 2011/12, scoring eight tries in 25 games as he played a big part in the region's fourth league title success.
However, a cartilage injury sustained in November 2012 saw him ruled out for a whole year, returning to action earlier this season. In total, he has scored 15 tries in 56 regional appearances, reaching his half century against Munster at the Liberty Stadium two months ago.
Andy Lloyd, Rugby Operations Manager, welcomed the announcement, saying:
"It's fantastic news that we have been able to secure Hanno and ensure he remains in this environment for the next three years.
"He's had a difficult time with injury and we have had to manage him on a daily basis since he returned to playing, but he is someone who can really establish himself at the top end of the game over the next three years. He is still only 23, so although he has already gained a considerable amount of top level experience, his best days are very much ahead of him, something that is true about a number of players in our squad.
"He has a real physicality, a forceful nature to his game, and a 'go-forward' attitude that can be crucial to how we want to play the game as a team. There are areas of his game where he needs to work hard, but that is where his time out has been very helpful towards his development as it's allowed him to educate himself more behind the scenes, and to understand the game in a different way.
"I think that will help him become a more mature, rounded player over time and that is a prospect that genuinely excites me and should excite all Ospreys supporters."
The other 12 players to have signed new contracts are Alun Wyn Jones, Sam Lewis, Ashley Beck, Eli Walker, Jonathan Spratt, Ben John, Ryan Bevington, Dmitri Arhip, Nicky Smith, Dan Baker, Dan Suter and Lloyd Peers. Matavesi is one of five new signings also confirmed, along with Rynier Bernardo, Dan Evans, Sam Parry and Gareth Thomas.
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