伊利亚姆纳湖是美国的湖泊，位于阿拉斯加州西南部，长124公里、宽35公里，面积2,622平方公里，海拔高度14米，平均水深44米，最大水深301米，蓄水量115立方公里。

Iliamna Lake or Lake Iliamna is a lake in southwest Alaska, at the north end of the Alaska Peninsula, between Kvichak Bay and Cook Inlet, about 100 miles (160 km) west of Seldovia, Alaska.

It is the largest lake in Alaska, second largest lake in the United States, and eighth largest in North America. (While all five Great Lakes are considerably larger, only Lake Michigan lies completely within US territory.) Covering about 2,600 km² (1,000 sq. miles), Iliamna Lake is 77 miles (124 km) long and up to 22 miles (35 km) wide, with a maximum depth of 988 feet (301 m). Through the Kvichak River, its waters drain into Bristol Bay.