The Scottish Premier League champions will travel to Sweden for the first leg on either August 21 or 22 as they hope to reach the group stages of the elite tournament.
FC Braga will have to defeat Cluj in order to gain a place in the next round, while Spartak Moscow will have to overcome Fenerbahce to gain a place in the group phase.
The return legs are expected to take place on August 29 and 30.
Champions League playoff fixtures:
FC Basel vs. Cluj
Helsingborgs vs. Celtic
Bate vs. Hapoel
AEL Limassol vs. Anderlecht
Dinamo Zagreb vs. NK Maribor
Braga vs. Udinese
Spartak Moscow vs. Fenerbahce
Malaga vs. Panathinaikos
Borussia Monchengladbach vs. Dynamo Kyiv
Lille vs. FC Copenhagen