0915 GMT January 19, 2020
The Dutch side does not get automatic entry into the group stages despite winning the Eredivisie for the 34th time and coming within seconds of reaching the Champions League final, AFP reported.
If the Dutch side beats PAOK, Erik ten Hag's team will still need to win a playoff to join the likes of Liverpool, Real Madrid and Juventus in the main competition.
It is not the easiest of ties for Ajax which has already lost several players from its exciting young squad.
Central defender Matthijs de Ligt has left for Juventus while midfielder Frenkie de Jong has joined Barcelona.
PAOK went unbeaten on its way to winning the Greek Super League, finishing five points ahead of Olympiakos as it conquered its first league title in over three decades.
The first leg will be played at PAOK's Toumba Stadium on August 6 or 7 with the return in Amsterdam a week later.
Two-time European champion Porto, which finished two points behind champion Benfica in Portugal, will face Krasnodar, which finished third in Russia while Belgian runner-up Club Brugge will meet its Ukrainian counterpart Dynamo Kiev.