The remaining four clubs in the tournament discovered their semi-final opponents during the draw today, with Hearts receiving a home tie against Inverness.
The Premiership outfits secured victories over Motherwell, Morton, Dundee United and Hibernian respectively to reach the semi-final stage.
Aberdeen remain the most successful club in the League Cup having snatched the title five times, while Hearts have not clinched the trophy since the 1962-63 campaign.
If Inverness see off Hearts, they will be finalists for the first time, while St Johnstone have come away as runners-up twice in the competition.
The ties will be played on the weekend of February 1 and 2.