Colfax is a city in Placer County, California, at the crossroads of Interstate 80 and State Route 174. The population was 1,963 at the 2010 census. The town is named in honor of U.S. Vice President Schuyler Colfax (1869–73), a bronze statue of whom stands at Railroad Street and Grass Valley Street.

Placer County Transit is the operator of mass transportation for western Placer County, California, excluding the city of Roseville, which has its own public transit system. In addition to six local routes, Placer County Transit also operates the Lincoln School Tripper in Lincoln, California, a bus supplement during school days, and the Placer Commuter Express, a commuter bus service between Downtown Sacramento and the Colfax Amtrak station. In addition to their fixed route service, Placer County Transit also operates Dial-a-ride services in local communities.