The North Fork Payette River (/peɪˈɛt/) is a river in the western United States in western Idaho. It flows about 113 miles (182 km) southwards from the Salmon River Mountains to near Banks, where it empties into the Payette River, a tributary of the Snake River. It drains a watershed of 912 square miles (2,360 km²), consisting of mountains and forests, and valleys filled with large lakes and wetlands.

It rises at the confluence of Trail Creek and Cloochman Creek, in a meadow in the Payette National Forest in Valley County. The river flows south into Upper Payette Lake, then further south through a narrow valley into Payette Lake, with a surface elevation of 4,990 feet (1,520 m) above sea level. The river exits from the southwestern corner of the lake at McCall and flows southwards through Long Valley into Lake Cascade, a large reservoir formed by Cascade Dam. The Lake Fork and Gold Fork rivers join from the north and east sides of the lake.^[5]

About five miles (8 km) below the Cascade Dam and the town of Cascade, the North Fork reaches the end of Long Valley and enters a narrow canyon along the western side of the North Fork Range in the Boise National Forest. Paralleled by State Highway 55, it crosses into Boise County, where the canyon's depth exceeds 2,500 feet (760 m).

The North Fork joins with the Payette River at Banks (2,825 feet (860 m)). From there, the Payette River flows 62 miles (100 km) further west to its confluence with the Snake River at Payette, just northeast of Ontario, Oregon.^[5]

• Columbia River
• List of rivers of Idaho
• List of longest streams of Idaho