Riley Creek is a tributary of Middle Creek, which in turn is a tributary of the Tahltan River, part of the Stikine River watershed in northwest part of the province of British Columbia, Canada. It flows generally south for roughly to join Middle Creek about north of Middle Creek's confluence with the Tahltan River. Riley Creek's watershed covers , and its mean annual discharge is estimated at . The mouth of Riley Creek is located about north of Telegraph Creek, British Columbia, about southwest of Dease Lake, British Columbia, and about east of Juneau, Alaska. Riley Creek's watershed's land cover is classified as 39.9% shrubland, 36.8% conifer forest, 20.3% mixed forest, and small amounts of other cover.
Riley Creek is in the traditional territory of the Tahltan First Nation, of the Tahltan people.
Riley Creek originates on the southeast edge of the massive Level Mountain shield volcano, about southeast of Meszah Peak, the highest peak of the Level Mountain Range, a cluster of bare peaks on the summit of Level Mountain. From its source near Classy Creek, Mansfield Creek, and Hartz Creek, Riley creek flows generally south and through a forested gorge to Middle Creek, which in turn empties into the Tahltan River.