A ~600 kyr long scanning X-ray fluorescence record of redox variability from the Cariaco Basin, Venezuela, provides insight into rapid climate change in the tropics over the past five glacial-interglacial cycles. Variations in the sediment accumulation of the redox-sensitive element molybdenum (Mo) can be linked to changes in Intertropical Convergence Zone migration and reveal that millennial-scale variability is a persistent feature of tropical climate over the past 600 kyr, including during periods of interglacial warmth. This new record supports the idea that high-frequency tropical climate variability is not controlled solely by ice volume changes, with implications for the role of high-latitude forcing of Intertropical Convergence Zone position and tropical hydrology on millennial timescales.