Marine Isotope Stage 3 (MIS 3), ~60,000–25,000 years ago, was marked by abrupt climate shifts, unstable ice sheets, and major sea-level variability. While long viewed as a period of low sea level, new evidence suggests global mean sea level (GMSL) may have been up to 20–30 meters higher than previously thought. This session invites studies on MIS 3 sea-level fluctuations, their timing, amplitude, and links to climatic drivers such as Dansgaard–Oeschger cycles, Heinrich events, and monsoon variability. We welcome contributions using diverse proxies—shoreline, geomorphic, speleothem, coral, and GIA modeling—as well as ice sheet reconstructions. Regional case studies from tropical, mid-latitude, and glaciated zones are encouraged. Syntheses integrating climate, ocean, and ice sheet dynamics are also welcome. The goal is to refine our understanding of MIS 3 sea-level changes and their relevance for Earth system feedbacks. The session will be done in collaboration with participants from IGCP 725 team.