The Wildeshausen Geest (German: Wildeshauser Geest) is part of the northwest Germany's geest ridge, that begins near Meppen on the river Ems with the Hümmling, is broken by the Weser depression, continues with the Osterholz Geest and reaches the marshes of Kehdingen by the river Elbe with the ridges of the Wingst and Stade Geest. It gives its name to the eponymous nature park.
The term geest is a substantivisation of the Low German adjective güst, which means "dry and infertile". It is an Old Drift landscape, characterised by the sandy depositions of the Ice Age. In the depressions between them are wet meadows and, where drainage is poor, bogs.
To the north the Wildeshausen Geest borders on the coastal marshes, to the south on a belt of wetland, which includes the Großes Moor , the Wietingsmoor and the Sulinger Moor, which reaches as far as the Wiehen Hills. The geest plateaux lie mainly at an elevation of 50 to 60 metres above sea level (Normalnull), but reach elevations even as high as 80 metres in the southeast Nienburg, an area which is outside the Nature Park itself. The striking eastern edge of the geest rises between Hoya and Syke about 40 metres above the Weser Lowlands, west of Syke the land is still about 20 to 30 metres high. On the southern perimeter there is a height difference of 20 metres in places, but often no difference at all.