The U.S. Geological Survey (USGS) in cooperation with the California State Water Resources Control Board collected produced water and casing gas samples from oil wells and injectate stored in surficial tanks planned for underground injection in the Orcutt Oil Field in Santa Barbara County in 2018. Samples were collected from the Orcutt Oil Field on February 6th and February 7th, 2018. This digital dataset contains the site information, analyzing laboratories and methods, and water and gas chemistry and quality-control results for these samples. Chemistry results include concentrations of dissolved noble and hydrocarbon gases and their isotopic composition; concentrations of inorganic constituents including salinity, major and minor ions, trace elements, and nutrients; low molecular weight organic acids; dissolved organic carbon and optical properties of dissolved organic carbon; stable isotopes of water, strontium dissolved in water, and carbon in dissolved inorganic carbon; and radium isotopes. Samples were analyzed in the field and by eight laboratories operated or contracted by the USGS.