Kenny Shiels guide Killie to the League Cup semi-finals, beating rivals Ayr United. Despite the win, Shiels criticised rival team tactics, believing the club should have done more. On 18 February 2012, Kilmarnock beat Rangers 1–0, with Shiels' son Dean scoring in the 12th minute, making him the first Kilmarnock manager to beat Rangers twice in one season. After the match, Shiels said a win over Rangers was dedicated to the club's supporters and praised his son, who scored the only goal in the match, for his performance as "outstanding". On 18 March 2012, Shiels' Kilmarnock side travelled to Hampden Park for
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