2012 would prove to be McFadden's most successful season for Donegal. In helping Donegal to back-to-back Ulster titles in 2011-2012, McFadden became the first Donegal footballer to twice finish top scorer in the Ulster Championship. He scored six points in the final against Down. He scored an unusual goal in the seventh minute of Donegal's All-Ireland Senior Football Championship quarter-final defeat of Kerry at Croke Park, later describing it as "fortunate". He was also involved in the semi-final victory over Cork. Then he scored Donegal's second goal of the 2012 All-Ireland Senior Football Championship Final. Patrick McBrearty's attempt at scoring a point came crashing off the Mayo post after eleven minutes of the game, and Mayo's Kevin Keane fumbled, dropping the ball into the path of Colm McFadden who promptly slotted it into the back of the net. His goal helped Donegal win the Sam Maguire Cup and was part of a total of 1–4 (including three frees) which McFadden scored during the game. McFadden later added an All Star and was named 2012 Ulster GAA Player of the Year. However, he was unable to attend the Football Tour of New York. He was shortlisted for All Stars Footballer of the Year, but the award went to team-mate Karl Lacey.