The Pioneer Oil Refinery was the first successful oil refinery in California, built in 1876 off Pine Street in Newhall, Santa Clarita, California.

The Pioneer Oil Refinery was designated a California Historic Landmark (No.172) on March 6, 1935.

The Lang Southern Pacific Station railroad line served the refinery.

In 2020, the refinery was added to the National Register of Historic Places; it is the only site on the National Register of Historic Places within the city of Santa Clarita.

The large kettles used to refine the crude oil in to kerosene and benzene are still on the site, along with an old wooden drill tower.