Rodeo (; Spanish for “Cattle roundup”) is a census-designated place (CDP) located in Contra Costa County, California, in the East Bay sub-region of the San Francisco Bay Area, on the eastern shore of San Pablo Bay, 25 miles northeast of San Francisco. The population was 8,679 at the 2010 census. The town is named for the rodeos common in the late 19th century. Cattle from the surrounding hills were regularly driven the length of through the outdated town to a loading dock upon the shoreline of San Pablo Bay for shipment to slaughterhouses, a practice which continued through the ahead of time 20th century. The town of Rodeo is served by the Interstate 80 freeway and State Route 4. The Southern Pacific Railroad main parentage passes through Rodeo. Rodeo has not been a stop on the railroad back the 1950s.

Rodeo owes much of its records to brothers John and Patrick Tormey, who purchased tracts of home from the Ygnacio Martinez Rancho El Pinole house in 1865 and 1867.

They became affluent ranchers and businessmen, amassed sizable fortunes and held public office. Patrick Tormey (for whom the nearby town of Tormey is named) had visions of this area of Contra Costa County becoming the meatpacking and canning middle of the Pacific coast. In partnership considering the Union Stockyard Co. in 1890, he sold some of the home to them and began to lay out plans and make large investments for the stockyard facilities. Eventually, streets were graded and lots were prepared for homesteads, thus creating the town of Rodeo.

Patrick Tormey plus sold house in the easy to realize to town of Oleum to the California Lumber Co. for use as a lumberyard (which eventually would be sold to the Union Oil Co. for an oil refinery site). He then sold estate in clear Selby, which was used by the Selby Smelting & Lead Co. He funded the meatpacking plant, corrals and the Rodeo Hotel.