Hjaltadalur is a valley on the east side of Skagafjörður, Iceland that was previously a part of Hólahreppur.

[1] Hjaltadalsá river runs through the valley, originating at Hjaltadalsjökull glacier located at the head of Hjaltadalur.

The Landnámabók states, "Hjalti, the son of Þórður skálpur came to Iceland and settled Hjaltadalur upon the advice of Kolbeinn and he lived at Hof; his sons were Þorvaldur and Þórður, both great men.

"[3] The bishop's residence, and later the school, in Hólar í Hjaltadal is in the middle of the valley and leaves quite an impression.

The mountain overlooking Hólar is called Hólabyrða and is 1,244 meters (4,081 feet) tall.