ESL One Cologne 2015 was the sixth Counter-Strike: Global Offensive Major Championship that was held from August 14–18, 2015 at the Lanxess Arena in Cologne. It was organized by Electronic Sports League.
Eight teams were in the playoffs. Fnatic, Luminosity Gaming, Natus Vincere, Ninjas in Pyjamas, Team EnVyUs, Team SoloMid, and Virtus.pro were returning Legends. Team Kinguin was the only new Legend in the tournament, replacing mousesports, which failed to make the top eight. Fnatic, which defeated Luminosity Gaming and Virtus.pro, was the winner of the event after defeating Team EnVyUs, which defeated Natus Vincere and Team SoloMid, 2–0. Fnatic was the first team to have consecutive major titles and would be the only team to do so until SK Gaming (which was Luminosity Gaming at this tournament) when the Brazilian team won MLG Columbus 2016 and ESL One Cologne 2016.