McInerney is the Ospreys' third signing of the close season
The Ospreys have signed former Ireland Under-20 lock Conor McInerney from Heineken Cup champions Leinster.
The 22-year-old captained his country at age-grade levels and played all five Under-20 Grand Slam matches in 2007.
"Our expanding scouting network has identified him as an outstanding medium-term prospect," said Ospreys elite performance director Andrew Hore.
"He is a robust, hard-nosed and uncompromising player with excellent line-out ability."
McInerney is the Ospreys' third new signing ahead of next season, following on from former All Black Jerry Collins and Tom Isaacs.
"I'm really excited about signing for the Ospreys and being part of what they are trying to build," stated McInerney.
"I can't wait to join up with the squad for the first time next month. The Ospreys are an ambitious organisation with first-class facilities, a talented squad and good coaches so it was an easy decision to make.
"I realise that the competition for places there is intense, with Lions and Welsh internationals in the second row, but I'm really looking forward to the challenge of establishing myself at the Ospreys over the coming years."