The Dons will face Morton after beating St Johnstone 1-0 at Pittodrie in the Betfred Cup.
The sides have not played each other since Aberdeen won a League Cup second round tie 2-0 in 2012.
The Dons last won the League Cup in 2014 at Parkhead, beating Inverness 4-2 on penalties.
The semi-final will be played on the weekend of October 22.
The venue for the match is still to be determined.
The other semi-final will see Celtic play Rangers in what is no doubt going to be another fiery affair.