The 24-year-old Canada internationalist moves to the Balmoral Stadium after leaving Dundee United just before the closure of the transfer window.
Manager Paul Hartley told the club website: “We are delighted to have added a player of Fraser’s quality to our squad. We only found out in the last couple of days that he might be available so I can only thank the chairman and the other directors for all they did to get a deal agreed.”
