Aasleagh Falls (Irish: Eas Liath , meaning "grey waterfall") sits on the River Erriff just before it meets Killary Harbour on the border of Counties Galway and Mayo in western Ireland.

The falls cascade dramatically over a series of rocky steps, and are particularly impressive after heavy rainfall. The surrounding landscape of rugged mountains and ancient forest is characteristic of Connemara.

The site is popular with hikers, anglers, and wildlife enthusiasts. Salmon can be seen leaping the falls, especially around June, and native birds and mammals frequent the area.

A signposted walking trail leads to a viewing platform above the falls, and visitors can also take in the scene from the nearby bridge.

The Western Way long-distance trail begins here, running 12 km through the Erriff Valley past Devilsmother Mountain to Sheeffry.