Railroad Addition Historic District, Historic district in Flagstaff, Arizona, United States

Railroad Addition Historic District is a protected area in downtown Flagstaff with buildings constructed of brick, stone, and iron. The structures follow strict construction regulations introduced starting in 1897 that shaped this neighborhood's appearance.

The district is listed on the National Register of Historic Places since January 18, 1983. Its original boundary ran roughly along the Santa Fe railroad tracks, Agassiz and Beaver Streets, and Birch and Aspen Avenues. It was expanded twice, adding nine buildings along Phoenix Avenue from Beaver Street to San Francisco Avenue and a building at 122 East Route 66.

The district's name comes from the railroad addition platted alongside the Atchison, Topeka and Santa Fe tracks. Its commercial blocks carry the names of late-1800s and early-1900s businessmen: John W. Weatherford, builder of the Weatherford Hotel, the Babbitt brothers David, George, William and Charles, and Thomas E. Pollock Sr.

The area is walkable and easy to explore since buildings are concentrated in a relatively compact space. The restored train depot nearby now serves as a transportation hub and visitor center with helpful information.

The district was listed on the National Register of Historic Places on January 18, 1983, and later enlarged twice: nine buildings along Phoenix Avenue between Beaver Street and San Francisco Avenue, plus a building at 122 East Route 66. The original boundary ran roughly along the Santa Fe railroad tracks, Agassiz and Beaver Streets, and Birch and Aspen Avenues.