Electronic Sports League One Katowice 2015, known as ESL One Katowice 2015 for short, was a Counter-Strike: Global Offensive (CS:GO) Major tournament that was from March 12-15, 2015 at the Spodek Arena in Katowice, Silesian Voivodeship, Poland. It was the first CS:GO Major of 2015.
It was organized by Electronic Sports League with sponsorship from Valve Corporation. The tournament had a total prize pool of $250,000 USD.
The first, round-robin group stage consisted of 16 teams in four groups. For the next stage the top two teams in each group were then seeded into a single-elimination bracket.