Oceanic circulation in the North Atlantic transports huge amounts of water, heat, salt, carbon, and nutrients around the globe. As such, changes in the strength of oceanic currents can yield profound changes in both North American and European climate, in addition to affecting the African and Indian summer monsoon rainfall. In this study, we used geochemical evidence to highlight a slowdown in the North Atlantic Ocean circulation over the last century. This change appears to be unique over the last 1,500 years and could be related to global warming and freshwater input from ice sheet melt. Based on our data, we also suggest that the period often called “The Little Ice Age” was characterized by a slowdown, of less amplitude than the modern weakening, in the North Atlantic Ocean circulation. Thus, our results contribute to ongoing investigations of the state of the circulation in the North Atlantic by providing a robust reconstruction of its variability over the last 1,500 years.