It is the first time since 2015-16 that Celtic aren't involved in the final of the tournament.
After St Johnstone sealed their place in the showpiece event with a stunning win over Hibs on Saturday, St Mirren and Livingston were looking to have the chance to get their hands on the trophy.
The Buddies won the trophy in 2013 but won't have the chance to do so again after Scott Robinson's early strike saw the Lions make the final for the second ever time.
The final between St Johnstone and Livingston will take place at the end of February.
January 24, 2021