The termination of the penultimate glacial period (TII) shows both similarities and differences to the last termination (TI). Both terminations show significant cold reversals in the postglacial warming trend. TI consists of a continuously increasing sea-level trend, whereas TII may demonstrate a sea-level reduction midway through the termination. We present a new, continuous sea-level record for TII derived from Red Sea δ18O records that supports the existence of the TII sea-level reversal. The record gives an unprecedented look at the structure of the TII sea-level reversal, which consists of an early highstand lasting several millennia in duration, followed by a 30 ± 12 m to 40 ± 12 m reduction in sea level and a stillstand of several millennia, before the final sea-level rise to the marine oxygen isotope stage (MIS) 5e interglacial. We suggest that there is a link between the sea-level reversal and internal, millennial-scale variability in the climate system.