Walnut Creek is a city in Contra Costa County, California, United States, located in the East Bay region of the San Francisco Bay Area, about 16 miles (26 kilometers) east of the city of Oakland. With a total population of 70,127 per the 2020 census, Walnut Creek serves as a vibrant hub for its adjoining cities because of its location at the junction of the highways from Sacramento and San Jose (I-680) and San Francisco/Oakland (SR-24), and its accessibility by BART. Its active downtown neighborhood features hundred-year-old buildings and extensive high-end retail establishments. The city shares its borders in imitation of Clayton, Lafayette, Alamo, Pleasant Hill, and Concord.

There are three bands of Bay Miwok Native Americans united with the Place of Walnut Creek (the stream for which the city is named): the Saclan, whose territory lengthy through the hills east of present-day cities of Oakland, Rossmoor, Lafayette, Moraga and Walnut Creek; the Volvon (also spelled Bolbon, Wolwon or Zuicun), who were near Mt. Diablo; and the Tactan, located on the San Ramon Creek in present-day Danville and Walnut Creek.

The city of Walnut Creek has developed within the earlier area of four extensive Mexican house grants. One of these home grants – measuring 18,000 acres (73 km) – belonged to Juana Sanchez de Pacheco. The inherit was called Rancho Arroyo de Las Nueces y Bolbones, named after the principal waterway, Arroyo de las Nueces (Walnut Creek in English), and for the local outfit of Volvon original Americans (also known as Bolbones in Spanish). The Arroyo de las Nueces was named for the local species of walnut tree, the California Walnut. The two grandsons of Sanchez de Pacheco inherited the thousands of acres of land. One, Ygnacio Sibrian, built the first roofed house in the valley in not quite 1850.

As settlers from the United States arrived with US annexation of California after victory in the Mexican–American War, a little settlement called “The Corners” emerged. It was named for the junction where roads met from the settlements of Pacheco and Lafayette. The intersection of Mt. Diablo Boulevard and North Main Street is now at this site. The first town settler was William Slusher, who built a dwelling upon the bank of Walnut Creek, first called “Nuts Creek” by Americans in 1849. In 1855, Milo Hough of Lafayette built the hotel named “Walnut Creek House” in The Corners. A blacksmith shop and a accrual were soon time-honored by settlers. In 1850 Hiram Penniman laid out the town site and realigned Main Street to what it is today. (Penniman then developed Shadelands Ranch.)