Isernhagen (Eastphalian: Isernhogen) is a municipality in the district of Hanover, in Lower Saxony, Germany.

It is adjacent to  Burgwedel, Burgdorf, Lehrte, Hannover, Langenhagen und Wedemark.

Isernhagen consists of 7 districts: Twinned with Peacehaven in East Sussex, Épinay-sous-Sénart in France, Suchy Las in Poland and Tamási in Hungary.

Explanation of coat of arms: The three lilies on red in the top right half, are taken from the coat of arms of the once residential Barons of Cramm and they are symbols for the three local congregations of the former joint municipality Kirchwarmbüchen.

In between meanders the silver band of the river Wietze, which connects all villages of the joint municipality.