Selby is an unincorporated community in Contra Costa County, in the East Bay region of the San Francisco Bay Area in northern California.

[1] The town is located on the Carquinez Strait where its enters San Pablo Bay, across from Vallejo.

[1] It is next to Rodeo, on the Southern Pacific Railroad, and 6.5 miles (10.5 km) west-northwest of Martinez.

[3] Selby is located on the 19th century Mexican land grant Rancho El Pinole site, that was made to Ygnacio Martinez.

[3] Al Zampa, a bridge construction worker who played an integral role in the construction of numerous San Francisco Bay Area bridges, was born here in 1905.