In Leverkusen's first game of the 2014–15 season against SV Alemannia Waldalgesheim in the first round of the 2014–15 DFB-Pokal, Kießling scored five goals, including four in the first half, as Leverkusen won 6–0 against the Verbandsliga Südwest side. In the first leg of Leverkusen's Champions League play-off tie with Danish side F.C. Copenhagen, Kießling scored the German's opening goal of a 3–2 away win. In the first game of the Bundesliga season, he converted a Karim Bellarabi pass in the last minute of stoppage time to complete a 2–0 win over Borussia Dortmund. In the second leg of their Champions League play-off against Copenhagen, Kießling scored twice more as Leverkusen advanced to the group stages with a 7–2 aggregate victory. He scored his tenth goal of the season and earned his side a penalty in their second group match of the Champions League, a 3–1 home win over Benfica on 1 October. He finished the season with 19 goals in 48 matches.