Former Morton, Livingston and Brechin City full-back Michael Miller moves to Somerset Park after helping Raith Rovers win the League 1 title last season.
Also joining the Honest Men is former Rangers, St Mirren and Dumbarton midfielder Tom Walsh, who makes the switch south from Inverness Caledonian Thistle.
Manager Mark Kerr told the club website: "Michael had an injury when he was a youth at Celtic but he has come back from that and won three titles in his career.
"Tom has been one of the best players in the Championship over the last two seasons. He will bring goals and assists and we are looking strong in the forward areas.”