The Hallertau or Holledau is an area in Bavaria, Germany. At 178 km², it is listed as the largest continuous hop-planting area in the world. According to the International Hop Growing Convention, Germany produces roughly one third of the world's hops (used as flavoring and stabilizers during beer brewing), over 80% of which are grown in the Hallertau.
It is divided into several seal districts:
- Abensberg
- Altmannstein
- Au in der Hallertau
- Geisenfeld
- Hohenwart
- Langquaid
- Mainburg
- Nandlstadt
- Neustadt an der Donau
- Pfaffenhofen an der Ilm
- Pfeffenhausen
- Rottenburg an der Laaber
- Siegenburg
- Wolnzach