The Bering Strait Inflow (BSI) is a key conduit for poleward transport of heat and fresh waters into the Arctic with important implications for the polar sea-ice extent and albedo. A mechanistic understanding of BSI is essential for reliable predictions of future changes, but has been hampered by lack of long-term records. Here, we present a multi-proxy reconstruction of BSI dynamics spanning the past 24,000 years from the northern Bering Sea. Our records reveal pronounced BSI pulses during the Bølling–Allerød and mid-Holocene periods, which triggered extensive sea-ice retreat in the Chukchi and East Siberian Seas despite cool regional sea-surface temperatures. Climate simulations demonstrate that these pulses were driven by sea-level pressure gradients induced by westward shifts of the Aleutian Low. These findings establish a critical baseline for high-latitude climate feedbacks, demonstrating that atmospheric-driven BSI changes can accelerate regional Arctic ice loss independent of direct ocean warming.