Lost Creek is a tributary of the Koshin River in northwest part of the province of British Columbia, Canada.

[9] Lost Creek's watershed covers 70.0 km2 (27.0 sq mi),[6] and its mean annual discharge is estimated at 1.07 m3/s (38 cu ft/s).

The creek flows north and northwest, first through Level Mountain's high and relatively barren lava plateau, then through rugged forested terrain.

In its final 2 km (1.2 mi) Lost Creek enters the Koshin River's floodplain.

The historic Yukon Telegraph Trail, following the Koshin River, crosses Lost Creek near its mouth.