A multi‐disciplinary study of sea‐level and climate proxies, including bulk rock and clay mineral compositions, carbon isotopes, total organic carbon (TOC), Sr/Ca ratios, and macro‐ and microfaunal associations, reveals seven major sea‐level regressions in the southwestern Tethys during the last 10 million years of the Cretaceous: late Campanian (c. 74.2  Ma, 73.4–72.5  Ma and 72.2–71.7  Ma), early Maastrichtian (70.7–70.3  Ma, 69.6–69.3  Ma, and 68.9–68.3  Ma), and late Maastrichtian (65.45–65.3  Ma). Low sea levels are generally associated with increased terrigenous influx, low kaolinite/chlorite + mica ratios, high TOC and high Sr/Ca ratios, whereas high sea levels are generally associated with the reverse conditions. These sea‐level changes may be interpreted as eustatic as suggested by the global recognition of at least four of the seven major regressions identified (74.2  Ma, 70.7–70.3  Ma, 68.9–68.3  Ma and 65.45–65.3  Ma). Climatic changes inferred from clay mineral contents correlate with sea‐level changes: warm or humid climates accompany high sea levels and cooler or arid climates generally accompany low sea levels. PDF