The Scottish forward signed for the Saints from First Division side Hamilton in January 2012 on a two-and-a-half-year contract, but the club announced on Wednesday that he would be leaving St Mirren Park by mutual consent.
Imrie, who has also played for Clyde and Inverness Caledonian Thistle, made 44 appearances for Danny Lennon's side, scoring three goals.
The Saints are facing a summer of change, with up to 13 players thought to be leaving Paisley.
Craig Samson has signed for Kilmarnock, while Graham Carey and Sam Parkin have both been told they will not be handed new deals.
Meanwhile, back-up goalkeeper Grant Adam has been advised he is free to find another club, with David Barron and Lee Mair also thought to be leaving St Mirren Park.
Conor Newton, Paul Dummett and Esmael Goncalves are all returning to their parent clubs, while Sander Puri has left after an unimpressive season.