Wietze is a river of Lower Saxony, Germany, a tributary of the Aller.

[1] The river begins at the confluence of the Edder and Flöth northeast of Hanover near Altwarmbüchen [de], a district of Isernhagen.

From there it flows several kilometres to the west through the southern part of Isernhagen to Langenhagen and from there on only in a northern direction to just beyond the village of Wietze, where it merges with the River Aller flowing from the south.

In the second half of its course the Wietze forms a pronounced depression with a bog-like region known as the Wietzenbruch.

This is a region of extensive forest and fen woodland (Bruchwald) about 400 square kilometres (150 sq mi) in area.