Qal'at Najm (Arabic: قلعة نجم) is a castle located on the right bank of the Euphrates, near the town of Manbij in north Syria.

The oldest reference to Qal'at Najm in Arabic texts is Jisr Manbij, while the current name came only into popular use in the 12th century CE.

[1] Following the conquest of the region by the Umayyads, the castle was controlled by the Hamdanids and the Mirdasid dynasty, before passing into the hands of the nomadic tribe of the Banu Numayr.

[1] Qal'at Najm is a castle of the truncated cone type, similar to the Citadel of Aleppo and those of Hama and Homs.

Inside Qal'at Najm is a palace-bath complex, consisting of four wings opening to a central courtyard with a fountain.