Abstract <p>A new palynological, mineralogical and isotopic study of the Cormeilles-en-Parisis section (Paris Basin, France) was carried out, resulting in the recognition of the succession of climatic events at the Eocene–Oligocene transition (EOT) interval in the central part of the Paris Basin. The last Eocene warming period recorded in the marine section from Antarctica, stratigraphically dated to Chron C16n, is recognized in the Marnes à lucines Fm. The following cooling steps due to the formation of the Antarctic ice sheet (at the EOT) were recorded in the Marnes blanches de Pantin Fm as the minor isotope shifts (EOT-1 and EOT-2) and in the Argiles vertes de Romainville/Calcaire de Sannois and the Marnes à huîtres fms as the major events (Oi-1 and Oi-1a). Based on these new data, the Eocene–Oligocene boundary is now defined in the upper part of the Marnes blanches de Pantin Fm which is stratigraphically lower than previously accepted in the li-terature. In addition, significant events include levels composed exclusively of charcoal debris that mark this boundary and reflect extreme aridity that caused massive forest fires. The depositional environments have also been refined, such as the marine incursions, the importance of the opening of the lagoon to the sea and the origin of particle flows (marine rather than fluvial origin) for the lower Oligocene.</p>