The 29-year-old’s current deal was set to expire at the end of the season, but he will now remain with the club at least until 2013.
The right-back had a previous spell with St Mirren between 2003 and 2008 and returned to the Paisley club in June 2010 from Hibs.
Now he hopes to remain at the club beyond the one-year extension. The Irishman told the club’s website: “You don’t see players with the one club for so long these days. I went away for a couple of seasons and came back but St Mirren are a great football club, I can’t praise them highly enough to be honest.
“I feel very fortunate to have played here for seven years now and I’m delighted to extend that with hopefully a few more years after that again.
“I think I have plenty more years left in me as a football player so I’m happy for that to be at St Mirren and hopefully that starts with another successful year next season.”