It is bounded by (from the north and clockwise) the districts of Heidekreis, Celle, Gifhorn, Peine, Hildesheim, Hameln-Pyrmont, Schaumburg and Nienburg.

The district surrounds the city of Hanover and includes the outskirts of its metropolitan area.

The Leine river enters the district in the south, runs through Hanover and leaves to the north.

In the northwest is the Steinhuder Meer, a lake with an area of 32 km2 (12 sq mi), within the region known as the Hanoverian Moor Geest.

The lion was the heraldic animal of the Welfen family, which ruled the region from the Middle Ages until 1866.