Dean Shiels on as a 74th-minute substitute. Shiels scored his first goal for Kilmarnock in a 2–1 away defeat to Inverness CT. He scored a penalty in a 1–0 win over Hearts, after Marius Zaliukas fouled Paul Heffernan. Shiels signed for Kilmarnock on a permanent basis in January 2012. Shiels scored the only goal of the Scottish League Cup semi-final against Ayrshire derby rivals Ayr United on 28 January. He also scored the winning goal in a game against Rangers at Ibrox on 18 February, in Rangers' first game after entering administration. On 18 March, he played in the 2012 Scottish League
Dean Shiels cost-cutting that is due to take place at the club; manager Ally McCoist refuted this. On 8 February 2014, Shiels scored a hat-trick in the Scottish Cup, as Rangers won 4–0 against Dunfermline Athletic. On 10 June 2016, Shiels left Rangers after his contract came to an end. He had made 43 appearances for Rangers in his final season with the club, as they won promotion to the Scottish Premiership. On 25 August 2016, Shiels signed for Dundalk in the League of Ireland Premier Division citing the "lure of European football" as one of the things that attracted him to