The Brunau is a 11.0-kilometre (6.8 mi) long stream of Lower Saxony, Germany, in the district of Celle, on the Lüneburg Heath.

[2] The Brunau rises in the vicinity of Nindorf, flows initially northeast to south of Hetendorf [de] (a district of Südheide).

Here it swings east, runs past Bonstorf to the north and then continues in a southeastern direction.

Shortly before its mouth the Brunau merges with an old, now overgrown, meadow-irrigation channel.

The Brunau derives its name from its brown (Low German: bruun) water.