The Phanerozoic record of global sea-level change is reviewed, presenting a new sea-level record for the past 100 million years. Long-term sea level peaked at 100 ± 50 meters during the Cretaceous, suggesting lower ocean-crust production rates than previously thought. Sea level changes are linked to ice-volume variations on the 10⁴- to 10⁶-year scale, but on the 10⁷-year scale, temperature changes due to tectonically controlled CO₂ variations are responsible. Sea-level changes have influenced phytoplankton evolution, ocean chemistry, and sediment burial. Over the past 100 My, sea-level changes reflect global climate evolution from ephemeral Antarctic ice sheets to large Antarctic and variable Northern Hemisphere ice sheets. Sea-level fluctuations result from changes in ocean water volume or ocean basin volume. Water-volume changes are dominated by ice sheet growth and decay, while ocean basin volume changes are influenced by sea-floor spreading rates. Eustatic variations can be estimated using satellite measurements, tide gauges, and geological records. The most recent pre-anthropogenic sea-level rise began at 18 ka and can be measured by dating shoreline markers. Coral records provide reliable estimates but are limited by complex uplift/subsidence histories. Continental ice sheet growth and decay cause eustatic changes recorded in foraminifera chemistry. Oxygen isotope values provide a proxy for glacioeustasy but are subject to uncertainties. Unconformities in the stratigraphic record indicate eustatic changes. Backstripping is a technique used to quantify eustatic changes by accounting for sediment compaction and loading. The review presents a new eustatic record for the past 100 My, showing lower amplitudes on the 10⁷- to 10⁸-year scale than previously inferred. The Late Cretaceous sea level was 100 ± 50 m higher than today. Sea-level changes on the 10⁶-year scale are linked to ice-volume changes, with the EPR records being questioned due to methodological issues. Sea-level changes on the 10⁴- to 10⁵-year scale are controlled by astronomical variations. The study shows that sea-level changes on the 10⁶-year scale are linked to ice-volume changes, with the EPR records being inconsistent with the new data. Sea-level changes on the 10⁴- to 10⁵-year scale are influenced by Milankovitch cycles. The study shows that sea-level changes on the 10⁶-year scale are linked to ice-volume changes, with the EPR records being inconsistent with the new data. Sea-level changes on the 10⁴- to 10⁵-year scale are influenced by Milankovitch cycles. The study shows that sea-level changesThe Phanerozoic record of global sea-level change is reviewed, presenting a new sea-level record for the past 100 million years. Long-term sea level peaked at 100 ± 50 meters during the Cretaceous, suggesting lower ocean-crust production rates than previously thought. Sea level changes are linked to ice-volume variations on the 10⁴- to 10⁶-year scale, but on the 10⁷-year scale, temperature changes due to tectonically controlled CO₂ variations are responsible. Sea-level changes have influenced phytoplankton evolution, ocean chemistry, and sediment burial. Over the past 100 My, sea-level changes reflect global climate evolution from ephemeral Antarctic ice sheets to large Antarctic and variable Northern Hemisphere ice sheets. Sea-level fluctuations result from changes in ocean water volume or ocean basin volume. Water-volume changes are dominated by ice sheet growth and decay, while ocean basin volume changes are influenced by sea-floor spreading rates. Eustatic variations can be estimated using satellite measurements, tide gauges, and geological records. The most recent pre-anthropogenic sea-level rise began at 18 ka and can be measured by dating shoreline markers. Coral records provide reliable estimates but are limited by complex uplift/subsidence histories. Continental ice sheet growth and decay cause eustatic changes recorded in foraminifera chemistry. Oxygen isotope values provide a proxy for glacioeustasy but are subject to uncertainties. Unconformities in the stratigraphic record indicate eustatic changes. Backstripping is a technique used to quantify eustatic changes by accounting for sediment compaction and loading. The review presents a new eustatic record for the past 100 My, showing lower amplitudes on the 10⁷- to 10⁸-year scale than previously inferred. The Late Cretaceous sea level was 100 ± 50 m higher than today. Sea-level changes on the 10⁶-year scale are linked to ice-volume changes, with the EPR records being questioned due to methodological issues. Sea-level changes on the 10⁴- to 10⁵-year scale are controlled by astronomical variations. The study shows that sea-level changes on the 10⁶-year scale are linked to ice-volume changes, with the EPR records being inconsistent with the new data. Sea-level changes on the 10⁴- to 10⁵-year scale are influenced by Milankovitch cycles. The study shows that sea-level changes on the 10⁶-year scale are linked to ice-volume changes, with the EPR records being inconsistent with the new data. Sea-level changes on the 10⁴- to 10⁵-year scale are influenced by Milankovitch cycles. The study shows that sea-level changes