This dataset includes detailed stable isotope measurements (δ¹³C, δ¹⁸O) from individual planktic foraminifera collected at IODP Site 392-U1580 (40°47.15'S, 26°36.41'E, 2560 m water depth) during the Paleocene-Eocene Thermal Maximum (PETM). Analyses were done at the Department of Geoscience, Utah State University, using a special method that allows for very accurate measurements on small samples of calcium carbonate, with a precision of ±0.22‰ for δ¹³C and ±0.09‰ for δ¹⁸O. The dataset includes measurements on three species: Acarinina soldadoensis, Acarinina coalingensis, and Morozovella aequa from four key stratigraphic intervals. Single-shell data show two different groups of isotopic values at the start of the PETM, suggesting that mixing occurred between specimens from before and during the PETM due to bioturbation. This mixing quantification enables correction of bulk geochemical measurements. The data also demonstrate species-specific migration patterns, with Morozovella appearing only during the PETM warming, providing insights into planktic foraminiferal biogeography and paleoceanographic changes. Values are reported in per mil relative to the VPDB standard.