| Álafoss | |
| Location: | Southwest of Iceland |
| Coords: | 64.1666°N -21.6758°W |
| Map: | Iceland |
Álafoss (in Icelandic pronounced as /ˈauːlaˌfɔsː/; eel falls) is a waterfall on the river Varmá in Mosfellsbær, Iceland.
A wool factory of the same name has adjoined the waterfall since 1896, when a local farmer imported machinery to process wool using the energy from the waterfall.
During World War II, barracks were constructed there for British soldiers. Álafoss played a major role in the founding and growth of the town of Mosfellsbær.
The band Sigur Rós has a studio named Sundlaugin at Álafoss, and the otherwise untitled fifth track on the band's album is nicknamed after the area.
Mosfellsbær is also home to a football club named after the waterfall, Álafoss Football Club.