Grethem
Municipality
Coat of arms
Location of Grethem within Heidekreis district
Grethem Show map of Germany Grethem Show map of Lower Saxony
Coordinates: 52°43′N 09°35′E / 52.717°N 9.583°E / 52.717; 9.583
Country	Germany
State	Lower Saxony
District	Heidekreis
Municipal assoc.	Ahlden
Government
• Mayor	Udo Schönberg
Area
• Total	16.35 km2 (6.31 sq mi)
Elevation	24 m (79 ft)
Population  (2022-12-31)[1]
• Total	668
• Density	41/km2 (110/sq mi)
Time zone	UTC+01:00 (CET)
• Summer (DST)	UTC+02:00 (CEST)
Postal codes	29690
Dialling codes	05164
Vehicle registration	FAL, SFA
Website	www.grethem.de

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