Bayer 04 Leverkusen, officially known as Bayer 04 Leverkusen Fußball GmbH and commonly known as Bayer Leverkusen or simply Leverkusen, is a German professional football club based in Leverkusen, North Rhine-Westphalia. It competes in the Bundesliga, the top tier of German football, and plays its home matches at the BayArena.