RasenBallsport Leipzig e.V. (lit. 'Lawn Ball Sports Leipzig'), commonly known as RB Leipzig or informally as Red Bull Leipzig, is a German professional football club based in Leipzig, Saxony. The club was founded in 2009 by the initiative of the company Red Bull GmbH, which purchased the playing rights of fifth-tier side SSV Markranstädt with the intent of advancing the new club to the top-flight Bundesliga within eight years. The men's professional football club is run by the spin-off organization RasenBallsport Leipzig GmbH. RB Leipzig plays its home matches at the Red Bull Arena. The club nickname is Die Roten Bullen (German for 'The Red Bulls').

After its foundation, RB Leipzig quickly rose through the ranks of German football, starting in the fifth-tier NOFV-Oberliga Süd. The club achieved successive promotions the following years, eventually being promoted to the Bundesliga in 2015–16. In their debut top-flight season, they qualified to the UEFA Champions League for the first time in their history, following a runner-up finish. They also became a regular feature in the Champions League, reaching the semi-finals of the competition in 2020. The club won its first domestic honour, the DFB Pokal, in back-to-back seasons, 2022 and 2023.

RB Leipzig's entrance into the upper echelons of German football has proven controversial, as the club's heavy corporate influence is regarded by many Germans to be antithetical to the traditional ownership, structure and management of sports clubs in Germany. On the other hand, some have expressed appreciation for what they view as an honourable endeavour to establish a durable footprint for the Bundesliga in the former East Germany, which previously had been at best tenuous since German reunification.