Dean Shiels Cup Final, which Kilmarnock won after beating Celtic 1–0. Shiels was shortlisted for the SPFA Players' Player of the Year award, along with Jon Daly, Steven Davis and Charlie Mulgrew. Shiels rejected the offer of a new contract with Kilmarnock and left the club at the end of the season. Shiels signed for Rangers on 31 July 2012. Kilmarnock's chairman Michael Johnson believes Rangers had underestimate Kilmarnock to get Shiels. Shiels vowed to make the club win a trophy this season and revealed he turned down clubs around Europe, which he could even play in the Champions League; instead, preferring
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