Iliamna (Dena'ina: Illiamna) is a census-designated place (CDP) in Lake and Peninsula Borough, Alaska, United States.

Year-round residents largely pursue subsistence activities, while summer workers from other areas work in the lodges.

Around 1913, Herman Gartelmann, Jack Kinney, and Ed Ahola built a roadhouse here, taking advantage of air travel through Lake Clark Pass.

[7] Iliamna faces the prospect of developing into a mining town, as several multi-national companies plan to develop the area northwest of the village into one of North America's largest gold-copper-molybdenum mines.

The first company to submit plans to the State of Alaska is Northern Dynasty Minerals, a wholly owned subsidiary of Hunter Dickinson.

The Lake and Peninsula Borough, the region's governing body, passed a strong resolution in support of the mine's development, but the majority of the surrounding villages adamantly oppose it.

[5] Iliamna has a continental subarctic climate (Köppen Dfc) with mild summers and severely cold winters.

[9] Winters are sometimes very cold, and in some years there are even low temperatures below −40 °F (−40 °C), usually 32 days have a minimum 0 °F (−18 °C) or below annually, and the coldest temperature in a year can drop to −21 °F (−29 °C), so Iliamna falls in USDA Plant Hardiness Zones 4b.

[11] Iliamna receives 25.01 inches (635 mm) of annual precipitation, mostly between summer and fall.

The racial makeup of the CDP was 39.22% White, 50.00% Native American, and 10.78% from two or more races.