Chelsea have drawn Malmo, while Arsenal have been pitted against BATE Borisov in the last 32 of the Europa League.
Celtic, who were unseeded in the draw, play Valencia with the home leg scheduled for February 14 and the return match in Spain taking place seven days later on February 21.
Chelsea are away on February 14 and will host Malmo in the second leg at Stamford Bridge on February 21.
Arsenal are also away on February 14 but their second-leg clash with Belarusian side BATE will be played at the Emirates Stadium on Wednesday, February 20 at 5pm, a day earlier than the other Europa League last-32 ties.
UEFA rules stipulate that two teams cannot play in the city on the same night, so Chelsea - who also topped their group and play their second leg match at home - have been given priority to play on Thursday as they won last season's FA Cup.
Benfica were paired with Galatasaray, while Sporting Lisbon face an Iberian Peninsula clash against La Liga side Villarreal. Serie A side Lazio were drawn to play five-time winners Sevilla.
The Europa League final takes place on May 29 at Baku's Olympic Stadium in Azerbaijan.
Europa League last-32 draw in full:
Viktoria Plzen vs Dinamo Zagreb
Club Brugge vs Salzburg
Rapid Vienna vs Inter Milan
Slavia Prague vs Genk
Krasnodar vs Bayer Leverkusen
FC Zurich vs Napoli
Malmo vs Chelsea
Shakhtar Donetsk vs Eintracht Frankfurt
Celtic vs Valencia
Rennes vs Real Betis
Olympiakos vs Dynamo Kiev
Lazio vs Sevilla
Fenerbahce vs Zenit
Sporting Lisbon vs Villarreall
BATE Borisov vs Arsenal
Galtasaray vs Benfica