This is the repository for data used for analysis in “Zircon constraints on the eruptive sequence and magma evolution of rhyolites at South Sister Volcano, Oregon” submitted to Geochemistry, Geophysics, Geosystems. There are three datafiles. Dechert_TableS1.xlsx includes rock sample unit information and locations. Dechert_TableS2.xlsx includes the 230Th-238U isotope ratios as collected with the Stanford-USGS SHRIMP-RG, the isochron model slope and ages, and the Boehnke model slope and ages (Boehnke et al., 2016). Dechert_TableS3.xlsx includes the trace element and rare earth element concentrations collected with the Stanford-USGS SHRIMP-RG.