Southern Pacific #9 is a 4-6-0 oil-fired narrow gauge steam locomotive, built by the Baldwin Locomotive Works in November 1909.

It was originally built for the Nevada–California–Oregon Railway and was sold to Southern Pacific in the late 1920s.

The engine worked the rest of its career on the SP narrow gauge, except a brief season in 1953 when the locomotive was briefly loaned to the Plaster City railroad operated by the United States Gypsum Company.

In 1954, there was a plan to purchase a new narrow gauge diesel from GE as SP #1, to replace numbers #9, #8 and #18.

The engine was also used in the 1948 film 3 Godfathers, starring John Wayne, Pedro Armendáriz, and Harry Carey Jr.;[2] as well as cameoing the 1954 - 1957 TV western series Annie Oakley, starring Gail Davis.