Gronau is a former Samtgemeinde ("collective municipality") in the district of Hildesheim, in Lower Saxony, Germany. Its seat was in the town Gronau. On 1 November 2016 it was merged into the new Samtgemeinde Leinebergland.
The Samtgemeinde Gronau consisted of the following municipalities:
- Banteln
- Betheln
- Brüggen
- Despetal
- Eime
- Gronau
- Rheden
52°04′00″N 9°47′00″E / 52.0667°N 9.7833°E / 52.0667; 9.7833