The California State Railroad Museum is a transportation museum located in Old Sacramento, Sacramento, California. The museum's collection includes 21 restored locomotives and railroad cars, dating back to the 1860s, as well as exhibits and artifacts related to the history of rail travel in California and the western United States.

Visitors to the museum can take guided tours or self-guided tours of the exhibits, which include life-size replicas of early locomotives, a recreated passenger depot, and an operating telegraph office. The museum also hosts a number of special events throughout the year, such as train rides, holiday celebrations, and steam locomotive demonstrations.

One of the highlights of the museum's collection is the "Big Boy" locomotive, one of the largest and most powerful steam locomotives ever built. The museum acquired the locomotive in the 1960s and spent many years restoring it to operating condition. Today, the Big Boy can be seen on display in the museum's main exhibit hall.

The California State Railroad Museum also operates a separate facility, the Sacramento Southern Railroad, which offers train rides on a historic diesel locomotive and passenger cars. The train rides take visitors on a scenic tour along the Sacramento River, providing a unique way to experience the history of rail travel in California.