Grethem

{{Infobox German location

|image_coa = DEU Grethem COA.svg

|coordinates = {{coord|52|43|N|09|35|E|format=dms|display=inline,title}}

|image_plan =Grethem_in_HK.svg

|state = Niedersachsen

|district = Heidekreis

|Samtgemeinde = Ahlden

|elevation = 24

|area = 16.35

|postal_code = 29690

|area_code = 05164

|licence = FAL, SFA

|Gemeindeschlüssel = 03 3 58 011

|website = [http://www.grethem.de/ www.grethem.de]

|mayor = Udo Schönberg

}}

Grethem is a municipality in the district of Heidekreis, in Lower Saxony, Germany.