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.

The Cologne event was the first ESL tournament that required competitors to take drug tests, which all came up negative.

Team Kinguin was the only new Legend in the tournament, replacing mousesports, which failed to make the top eight.

The winner of those two matches then played each other to determine which team moved on to the playoff stage; the loser of this match received a "high seed" in the second group stage.

However, Nuke was taken out of the active map pool and Train was brought back in for the first time since the second Major, EMS One Katowice 2014.

Before each match in the group stage, both teams banned two maps.

[8] Hosts Analysts Commentators Observers Others All streams were broadcast on Twitch in various languages.