Provided here are in-situ Si and O isotope compositions of Detrital Jack Hills and Lachlan Fold Belt zircons. These data formed the basis of the research published as: Origin and significance of Si and O isotope heterogeneities in Phanerozoic, Archean, and Hadean zircon, Trail et al., (2018), PNAS 115 (41), 10287-10292 The data are provided in a single Excel spreadsheet, with multiple tabs, which are as follows: 1. Sample description and analytical method summaries 2. Solution and laser-fluorination data for characterisation of the standards used in the Ion Probe measurement sessions 3. Ion Probe (In-situ) Si and O isotope data for the Lachlan Fold Belt and Duluth Gabbro zircons 4. Ion Probe (In-situ) Si and O isotope data for the detrital Jack Hills zircons, as well as 207Pb/206Pb age estimates 5. Raw Ion Probe Si and O isotope data for LFB samples 6. Raw Ion Probe Si and O isotope data for Jack Hills samples 7. Ion Probe (In-situ) Si isotope data for the Lachlan Fold Belt zircons (utilising O- hyperion source)