State Route 161 is a California state highway running along the California-Oregon state line from U.S. Route 97 north of Dorris to the intersection of Route 139 and Oregon Route 39 north of Tulelake. Route 161 is part of the Volcanic Legacy Scenic Byway.

SR 161 is eligible for the State Scenic Highway System.

SR 161 begins at an intersection with U.S. Route 97 north of Dorris. The route travels east past Indian Tom Lake, bending to the south and passing by Lake Miller and Sheepy Lake. SR 161 continues past the Lower Klamath National Wildlife Refuge, which includes Lower Klamath Lake, and White Lake, now paralleling the state line again to the intersection of Route 139 and Oregon Route 39 north of Tulelake in the community of Hatfield.

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, and do not necessarily reflect current mileage. The entire route is in Siskiyou County.