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 Former Samtgemeinden in Lower Saxony