Twentieth Street Historic District, Historic district in West Adams, Los Angeles, California, US.

Twentieth Street Historic District is a collection of residential buildings in Craftsman and Prairie styles lining the 900 block in West Adams. The area contains houses from different building phases, each showing distinctive features from its era.

The houses on the 900 block of South 20th Street were built between 1900 and 1908 by contractor W. Wayman Watts in partnership with George Steckel. The row was listed on the National Register of Historic Places on June 22, 1991.

The block's mix of styles comes from builder W. Wayman Watts, who worked with George Steckel on these houses between 1900 and 1908. The Steckel House at 924 West 20th Street is named for that partner. The houses remain private homes, so visitors read the facades from the sidewalk.

The district sits about 0.75 mile (1.2 kilometers) north of the University of Southern California, positioned between Washington Boulevard and Toberman and Oak Streets. The area is easy to walk through and offers good views of the house facades from the street.

The Stevens-Brown House at 936 West 20th Street, built in 1903, is the block's only Transitional Victorian: a two-story frame and overlap-board house with a hip roof and a tent-roofed turret. The other five listed houses are Craftsman or Prairie designs.