Iron (Fe) is a key micronutrient regulating marine productivity and the global carbon cycle, yet reconstructing the relative contributions of different Fe sources through time remains challenging. Here we present high-resolution iron isotopic compositions (δ56Fe), measured by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), from a Fe-Mn crust sample (CXD31) recovered from the North Pacific Ocean, spanning the past ~23 Myr. The Fe isotopic values vary within the range of modern marine Fe sources, reflecting dynamic mixing among atmospheric dust, sedimentary inputs, and hydrothermal contributions. Using isotope mass-balance calculations, we reconstruct temporal changes in the relative importance of these Fe sources since the Miocene. Three intervals characterized by elevated δ56Fe values (~16.9, ~11.6, and ~2.7 Ma) indicate enhanced inputs of isotopically heavy Fe, which we attribute to increased aeolian dust supply linked to progressive aridification of inland Asia. These Fe isotope data provide a long-term record of Fe source variability in the North Pacific and offer new constraints on the coupling between continental climate evolution and oceanic Fe cycling.