The 30-year-old British and Irish Lions tighthead has made over 150 appearances for the Ospreys and is delighted to have secured a new contract.
"Obviously I'm delighted to have sorted out a new deal, which means that I'll continue playing for my home region for another two years," he said.
"This is where I always wanted to be next season and now it's all done, I just want to get on with the job, which is to help the Ospreys be the best we can be.
"As part of the contract discussions we spoke at length about the direction the Ospreys are taking, with the changes that are taking place, and I'm genuinely excited about the future, for the region and for myself personally.
"I can understand that fans may be frustrated at the moment but I genuinely think we are going in the right way. It's important that we have everyone going in one direction together, with everybody, youngsters and older players alike understanding that we're in this as a team.
"I've been a part of the region for a long time, first at Neath and then with the Ospreys, and although I've done a lot of things, there is still plenty I want to achieve with the Ospreys. I'm still ambitious, as are the Ospreys, and I'm excited about what we could achieve together over the coming seasons."
Hailing from Abercrave, Adam was one of the 'originals', joining the Ospreys from Neath RFC following the inception of regional rugby in 2003. He made his debut in their first competitive fixture, a 41-30 win over Ulster at the Gnoll, before going on to establish himself as a key player with both his home region and the national team.
Adam has also won 76 Wales caps, again getting two tries, in addition to two test appearances for the British and Irish Lions. Last month saw the launch of his Testimonial Year in recognition of his service to rugby in the region over the last 10 years.
Andrew Hore, Ospreys Chief Operations Officer, hailed the news as a positive sign of intent for the region:
"Adam has been, and continues to be, a fantastic servant for the Ospreys. As you would imagine given his status as one of the leading tight heads in world rugby, there was considerable interest in his services, but the fact that we have been able to keep hold of him is a huge positive for the region.
"It's important that we keep hold of individuals who want to take us forward as a region, who display the right values and characteristics to help us achieve that, demand the highest standards of both themselves and their colleagues, and have a desire to succeed. Adam certainly fits the bill on all those scores.
"He epitomises everything that we stand for. As a homegrown player proud to represent his region who has been developed from within to become such a fine ambassador for the game, he is an excellent role model to the younger players in the group. This is great news."