Hooker Scott Otten has signed a three-year deal with the Ospreys - his first professional contract with the region.
The 19-year-old came off the bench to make his debut in Ospreys' 34-9 win over Cardiff Blues in March.
Otten has also played for Swansea RFC and appeared for Wales Under-20s at the recent Junior World Championship in New Zealand.
"This is an exciting time for me and I'm proud to have signed a professional contract with my home region," he said.
"I've had an incredible few months, with making my senior debut in the Pro12 and going to New Zealand with Wales,
"But I've got to keep my feet on the ground and work hard to make sure it doesn't all go to waste."
The Ospreys have agreed new contracts with 16 players and have also announced six new signings for next season.