The Irish League 1905/06 was the 16th season of the highest all-Irish football league . Cliftonville FC and Distillery FC shared the championship title.
Eight teams played against each other twice on a total of 14 match days, divided into a first and a second round. The championship should be decided between teams with equal points in play-offs . Twice there was a tie. Since a third game could not be played because of the unrest, both clubs were declared champions.