In 2017, the Geological Survey of South Australia, in partnership with Geoscience Australia, undertook a regional drilling program in the far west of South Australia: the Coompana Drilling Project. The project sought to obtain geological information about the (then) almost completely unknown crustal entity known as the Coompana Province. This region of SA is completely covered by Neoproterozoic to Cenozoic sediments, and there are no known basement exposures. The primary objective of the project was to obtain high quality drill core samples from the basement units beneath the Nullarbor Plain. Eight new diamond drillholes penetrating basement were completed during the program. The Coompana Province is one of the least understood geological provinces remaining on the Australian Continent. It is situated at the nexus between the West, South and Northern Australian Cratons, and may record the final amalgamation of the proto-Australian Continent during the Mesoproterozoic. This report presents the results of U-Pb dating of the basement units using the Sensitive High Resolution Ion Microprobe (SHRIMP) and chemical abrasion thermal ionisation mass spectrometry (Ca-TIMS) methods. Fourteen samples were collected from seven of the eight new GSSA stratigraphic drillholes, and twelve of these samples have now been dated. In addition, stored drill chip samples from two existing historic water wells, Nullarbor Plains 7 and Albala–Karoo, were dated using SHRIMP. A stratigraphy for the eastern Coompana Province has subsequently been constructed based on the geochronology (this study), geochemistry and isotope geochemistry of lithological units identified during the Coompana Drilling Project. New stratigraphic units (defined elsewhere) include five rock suites and four formations.