Ki-a-Kuts Falls, Waterfall in Washington County, United States.

Ki-a-Kuts Falls is a 40-foot (12 m) waterfall on the Tualatin River in Washington County, Oregon, within the Tillamook State Forest. It drops in a single cascade down a narrow chute in basalt cliffs overhanging the river, ending in a pool at the base. The falls lie 1,700 feet (520 m) upriver (west) of the Tualatin's confluence with Maple Creek and 1.4 miles (2.3 km) north of Barney Reservoir, at an elevation of 1,299 feet (396 m).

Tualatin Riverkeepers explored and discovered the waterfall in 1993, bringing it to public attention for the first time. Official recognition by the U.S. Board on Geographic Names followed in 1999, marking its formal documentation.

The name honors Chief Ki-a-Kuts, the last leader of the Atfalati Kalapuyan people, whose history is rooted in this land. The falls serve as a reminder of the Native peoples who once lived throughout this region.

The falls lie in the Tillamook State Forest, about 3.5 miles west of the Washington–Tillamook county line and 1.4 miles north of Barney Reservoir. No maintained trail reaches the site; the 1993 discoverers waded up the Tualatin River itself. Expect dense forest, a concealed river bend and no facilities.

The U.S. Board on Geographic Names normally rejects hyphenated place names, but made an exception here at the request of the Confederated Tribes of the Grand Ronde, who also asked that the final syllable be spelled with a K rather than the C first proposed.