State Route 660 (SR 660) was a state highway in Reno, Nevada. Prior to decommissioning, the route encompassed the Sierra Street bridge over Interstate 80 near downtown Reno.

SR 660 comprised portions of former State Route 33A.

By the early 2000s, SR 660 ran along Sierra Street from 11th Street to State Route 430 (Business U.S. 395; Virginia Street).

Control of the Sierra Street bridge was relinquished to the city of Reno on January 11, 2011. SR 660 was completely retired from the state highway system at that time.