The scrum-half, who is currently with Italian side Zebre, has signed a two-year contract with the Pro12 side.
The 25-year-old told the club's website: "I'm excited about this fantastic opportunity with the Ospreys. Their record in the Pro12 speaks for itself and the chance to be a part of such a successful club is something I couldn't turn down.
"I've worked with [backs coach] Gruff Rees before, at Aironi, and It'll be great to work with him again along with the other coaches at the Ospreys.
"I'm looking forward to a new challenge in a competitive environment that will help me to improve as a player and a person while hopefully contributing to the continued success of the Ospreys."
The reigning Pro12 champions are currently fifth in the table.