Auschwitz II-Birkenau was a Nazi-German extermination camp, near Brzezinka, Poland, within the Auschwitz concentration camp complex during World War II.

Birkenau may also refer to:

• Birkenau (Odenwald), a municipality in the Odenwald in southern Hesse in Germany
• Brzezinka or Birkenau, a Polish village
• Birkenau (painting), a cycle of four paintings by Gerhard Richter