The Twin River is a tributary of the Iskut River in the northwest part of the province of British Columbia, Canada. From its source in Twin Glacier the Twin River flows south for about 11 km, east of Hoodoo Mountain to the Iskut River north of the Craig River watershed. The Twin River's watershed covers 203 km2, and its mean annual discharge is an estimated 16.7 m3/s . The river's watershed's land cover is classified as 77.2% snow/glacier, 9.8% barren, 4.5% conifer forest, and small amounts of other cover.
The mouth of the Twin River is located about 77 km (48 mi) east-northeast of Wrangell, Alaska, about 114 km (71 mi) northwest of Stewart, British Columbia, and about 130 km (81 mi) south of Telegraph Creek, British Columbia.
The Twin River is in the traditional territory of the Tlingit, specifically the Shtax'héen Ḵwáan, commonly known as the Stikine River people. It is also in the asserted traditional territory of the Tahltan First Nation and Iskut First Nation, of the Tahltan people.