State Route 177 (SR 177) is a short state highway in the U.S. state of California in Riverside County. The route links Interstate 10 midway between the Coachella Valley and Blythe on the California/Arizona border, to State Route 62 near Rice. SR 177 travels along the eastern portion of the Joshua Tree National Park. Route 177, like the eastern 100 miles (160 km) of SR 62, pass through some of the most desolate areas of the Mojave Desert. The southernmost portion of SR 177 near I-10 runs concurrently with County Route R2.

SR 177 begins at I-10 near Desert Center and briefly travels north, intersecting with CR R2. At this intersection, SR 177 turns northeast and travels across the Mojave Desert, through the Chuckwalla Valley. It passes near the Desert Center Airport and comes near Palen Lake, a dry lake. SR 177 passes along the southeastern boundary of Joshua Tree National Park before turning due north and crossing the desert for several miles. SR 177 briefly turns northeast again before intersecting with SR 62 and defaulting onto SR 62 eastbound.

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 Riverside County.