尼尔格谷（Nirgal Vallis）是一个位于火星科普来特斯区和凤凰湖区的古河道，中心座标28.4°S, 42°W，长496公里，以阿卡德语的火星命名。

尼尔格谷的西半部是树枝状水系系统，但东半部则是细而蜿蜒且侵蚀甚深的河谷。尼尔格谷终端和乌斯钵谷相接。该河谷支流相当短且源头相当类似于地球上的冰斗。

Nirgal Vallis is a long river channel bordering the Coprates quadrangle and Margaritifer Sinus quadrangle of Mars at 28.4° south latitude and 42° west longitude. It is 496 km long and is named after the word for "Mars" the god of war in Babylonian. Nirgal Vallis had a discharge of 4800 cubic meters/second. The western half of Nirgal Valles is a branched system, but the eastern half is a tightly sinuous, deeply entrenched valley. Nirgal Valles ends at Uzboi Vallis. Tributaries are very short and end in steep-walled valley heads, often called "amphitheater-headed valleys." The shape of these valley heads is like cirques on the Earth.