Nachtjagdgeschwader 100 (NJG 100) was a Luftwaffe night fighter-wing of World War II.

The Geschwader did not have a Stab and no Geschwaderkommodore.

It had two Gruppen (groups), operating separately.

The I. Gruppe of NJG 100 was formed in early 1943 from the II.

Gruppe was formed in July 1944 from three Staffeln of Nachtjagdgeschwader 200.