Cracknell, who started every game for Wales at the recent Junior World Championship in New Zealand, has penned his first pro contract which runs until the end of the 2016/17 season after the Ospreys beat off considerable competition to secure his services.
The 20-year old arrives at the Liberty Stadium via a personal journey that has taken him from Leeds where he was born to South Africa and North Wales.
Having been a part of the Leeds Carnegie Academy as a teenager he toured South Africa with Leeds Grammar School in 2012, playing five games, after which he was invited to spend 2013 with the Border Bulldogs Academy in East London where he played for the Currie Cup outfit's U19 team.
Welsh qualified through his grandfather, on his return to the UK in December he was invited to North Wales to sign for RGC in Colwyn Bay, where he caught the eye in the Swalec Championship. Just three months later he was called into the Welsh U20 squad for the first time as he made his international debut against Scotland in March.
At 1.91m tall and weighing 110kg, his physicality and work rate saw him quickly establish himself as first choice in the number six shirt for the national age-grade team and he started all five games for Wales last month.
"This is awesome for me personally, to have the opportunity to be a part of the Ospreys is unbelievable" said Cracknell after signing for the region.
"First and foremost now I have to work hard to keep developing, make a good impression on the coaches and then push myself into consideration. If I'm given the opportunity to play I'll need to make sure I take it.
"Hopefully I'll add something different to the mix and the coaches will like what they see of me but I realise there are quality players and internationals in my position so I know what the challenge in front of me is. It's an exciting opportunity.
"I've been all over the world playing rugby already, but I'm looking forward to making Swansea my home for at least the next three years and I'm really keen to get started. The U20 experience has been great for me, especially to play at that standard of rugby. There were six Ospreys boys in the squad as well so that will help me as there'll be some familiar faces in the environment. My first day can't come soon enough."
Cracknell will report for duty later this month following the delayed rest period given to those Ospreys on international action the summer, and Andy Lloyd, Recruitment and Retention Manager, said that the signing was a significant one given the interest in the player from other teams, inside and outside of Wales.
"Olly hasn't come through the traditional pathway, but he has created a real impression in the rugby community over the last year or so and we are delighted to have been able to secure his signature ahead of a number of interested clubs" said Lloyd.
"It's great that the WRU were able to identify him as Welsh qualified and bring him to Wales to play for the U20s. It's our job now to further his development and it's up to Olly to take this opportunity to secure a regional place and beyond that a senior national place. We can't wait to get him in and to work with him in our environment. He's a big lad, he's very physical,and will add more depth in what is already a competitive position for us in the back row.
"The strength of our development system is something we pride ourselves on, the record we have in developing local boys to not only play for the region but also for Wales speaks for itself. We realise though that there are always players out there that could make the step up who maybe have gone under the radar and it's important that we keep scouring for raw talent because it is out there, late developers, boys who sometimes miss out on age grade selection and the like.
"It's the reputation we have for development that attracts people like Olly to the Ospreys. For a young man he has been fortunate enough to experience different environments and is a very mature individual. We believe he is someone who with the right support can thrive on and off the field in our environment and we're delighted to have secured his services."
ENDS
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