"It feels great to sign the new contract, "Said Willow "I've been at Celtic for a while now and we managed to come to an agreement really quickly.
"I'm looking forward to spending at least the next three-and-a-half years here. I've always been a Celtic supporter and it was easy decision to sign the contract.
"I think the best years are still ahead of me with Celtic. I don't think defenders hit their peak until they get older and I don't think I've hit top form here by any means.
"There is a lot to look forward to and it's great that the manager has shown so much faith in me. I really appreciate it. I've had my fair share of injuries over the past few years, but to have the backing of everyone at the club really does mean a lot to me."
Wilson, who joined Celtic from Dundee United in January 2006, has been a great acquisition, especially since given his relative young age and injury troubles that saw him miss large portions of playing time with knee problems. Now 24, Mark is already looking back on three league titles, and one particular triumph sticks out for the affable young full back
He said: "There are so many highlights from my time at Celtic already. The stand-out is winning the title at Tannadice last season. It's a moment I will never forget.
"I think all the boys would say the same, though. It's the type of experience you could only get at Celtic. If you moved down south or abroad, you wouldn't get experiences like Tannadice or the European nights at Celtic Park.
"It will take a lot to beat the way we won the league last season, but if we go on to win a few more trophies this season then you never know.
"I've come a long way in the last three years. I've won trophies, I've played a few different positions and I think I've grown up a lot as well. But hopefully the best years are still come. I'm learning all the time under Gordon Strachan and Garry Pendrey and I want to keep doing that."
I for one am glad to have secured the services of this young player, who still has his best years ahead of him.
Yours in Celtic
Clydebuilt