The 33-year-old holds the record of most appearances for the Paisley side, having played 467 times.
"Shuggy has set himself in the record books at a club he has served terrifically well for 15 years," said Buddies boss Danny Lennon. "In the modern era, it is rare for a player to spend his whole career at the one club. I think that is to be praised and commended.
"Shuggy has now thrown down the gauntlet to our emerging young players, such as Jason Naismith and Thomas Reilly, encouraging them to be the next players to serve the club impeccably well in the years to come and to achieve legendary status at a club that is steeped in 135 years of rich footballing heritage.
"We wish Shuggy every success in the future and believe he will continue to make a positive impact on Scottish football in the years ahead."
Murray is expected to continue playing for another club next season.