He scored Celtic's winning goal in a 1–0 victory over Rangers in December 2011, a win which saw Celtic leap-frog their Old Firm rivals to first place in the league, and followed that up with another goal against Hearts in February 2012, before scoring again three days later against Inverness Caledonian Thistle. On 18 March 2012, Ledley played in another Scottish League Cup Final. However, for the second year running he was on the losing side as Celtic lost 1–0 to a late goal from Kilmarnock. The season did culminate in silverware for Ledley though, as Celtic won the Scottish Premier League for the first time in three years. The title was clinched on 7 April 2012 as Celtic crushed Kilmarnock 6–0 at Rugby Park, with Ledley scoring Celtic's fifth goal. After the match, Ledley described Celtic's title win as being "...one of the biggest achievements of my life", also adding that Celtic "...have been fantastic this season and we proved it again this time against a very good Kilmarnock team. We deserved it as we've played the best football in the SPL." In total, Ledley made 32 appearances in the league that season, scoring 7 times.