The 26-year-old becomes the eighth player to sign an NDC, following in the footsteps of captain Sam Warburton, Dan Lydiate, Jake Ball, Samson Lee, Rhodri Jones, Tyler Morgan and Hallam Amos.
The former Wales U20 and Wales Sevens international has started the last six games for his country, scoring three tries in that time.
Wales Head Coach, Warren Gatland, said: “Rhys has established himself as a proven international scrum-half and fully deserves a National Dual Contract.
“He has impressed at regional level for the Ospreys and this ensures his future here, which will prove an enormous benefit to professional rugby in Wales.”
Upon signing the contract Webb said: “I’m delighted to be the latest player to sign a National Dual Contract.
“I’m enjoying my rugby at the Ospreys and with Wales and this allows me to build on that. Now my future is confirmed, I can focus all my attention of becoming a better rugby player.”
Welsh Rugby Union Group Chief Executive, Roger Lewis, added: “Rhys Webb is a fantastic player and talent, who is a great addition to our list of National Dual Contracted players.
“We now have an incredible mixture of experience and youth who have committed their future to Wales and the Regions.”
Andrew Millward, Rugby General Manager, Ospreys Rugby, commented: “Rhys has really kicked on as a player and a person over the last season and a half, establishing himself firmly as an Osprey and within the national squad, and this has been recognised via an NDC. It’s great to see him committing himself to staying within Wales at his home region for the long term.”
Webb made his debut for Wales in the 2012 RBS 6 Nations at Italy and has 13 caps for his country. He was a key member of the Wales Sevens team that won the World Cup in Dubai during 2009.
Bridgend born Webb has come through the ranks at the Ospreys, playing regional age-grade rugby prior to signing a development contract ahead of the 2007/08 season. His senior debut came as a 19-year old, coming off the bench during a 32-7 win over Ulster at the Liberty Stadium in March 2008, and he has made 116 Ospreys appearances to date, scoring 20 tries.
