Haziga of Diessen, also known as Hadegunde (c. 1040 – 1 August 1104) was a Countess consort of Scheyern.
He was married three times; it is unclear in which marriage Haziga was born.
It was moved to Fischbachau in 1085, then to Petersberg, near Dachau in 1104 and finally to Scheyern in 1119.
With him, she probably had two sons and a daughter: Her second husband was Count Otto I of Scheyern (d. 4 December 1078).
He had four children; it is possible some or all of these were from his first marriage: Hans Constantin Faußner: Zur Frühzeit der Babenberger in Bayern und Herkunft der Wittelsbacher, Jan Thorbecke Verlag, Stuttgart, 1990, ISBN 3-7995-2413-4