Deimern is a village in the borough of Soltau in the Heidekreis district in the German state of Lower Saxony.
The hamlets of Timmerloh, Harmelingen and Grasengrund belong to the parish of Deimern.
Deimern lies on the Lüneburg Heath northeast of Soltau.
The district roads (Kreisstraßen) K 2 and K 3 cross near Deimern.
The Ehbläcksmoor nature reserve is located in the parish.