It is bounded by (from the north and clockwise) the districts of Landshut, Mühldorf, Ebersberg, Munich and Freising.

Erding was located on the way between two important centres of power in the Wittelsbach state, Munich and Landshut.

Slight modifications took place in the administrative reform of 1971, when some villages from neighbouring districts were awarded to Erding.

Several affluents of the Isar River cross the district from south to north, among them the Sempt.

A substantial part of this swampy area was drained in order to build the new airport of Munich, which opened in 1992.