Surface hotspot motions are approximately a factor of two faster in the Pacific than the Indo‐Atlantic, and the Indo‐Atlantic large low shear velocity province (LLSVP) appears to be significantly taller than the Pacific LLSVP. Hypothesizing that surface hotspot motions are correlated with the motion of plume sources on the upper surface of chemically distinct, intrinsically dense LLSVPs, we use 3D spherical mantle convection models to compute the velocity of plume sources and compare with observed surface hotspot motions. No contrast in the mean speed of Pacific and Indo‐Atlantic hotspots is predicted if the LLSVPs are treated as purely thermal anomalies and plume sources move laterally across the core‐mantle boundary. However, when LLSVP topography is included in the model, the predicted hotspot speeds are, on average, faster in the Pacific than the Indo‐Atlantic, even when modest topography is assigned to both LLSVPs (e.g., 100–300 km). The difference in mean hotspot speed increases to a factor of two for larger and laterally variable LLSVP topography estimated from seismic tomographic model S40RTS (up to 1,100–1,500 km for the Indo‐Atlantic region vs. 700–1,400 km for the Pacific region) and our results also broadly reproduce the convergence of Pacific hotspots toward the center of the Pacific LLSVP. These largescale features of global hotspot motions are only reproduced when ambient mantle material flows over large, relatively stable topographical features, suggesting that LLSVPs are chemically distinct and intrinsically dense relative to ambient mantle material. Plain Language Summary: Seismic observations reveal two continent‐sized anomalies at the base of the Earth's mantle, referred to as Large Low‐Shear‐Velocity Provinces (LLSVPs), through which seismic waves travel slowly. Slow seismic velocity is generally interpreted as increased temperature. However, buoyant plumes of hot material rise from the LLSVPs and produce hotspot volcanoes on the Earth's surface, and the geochemistry of these lavas suggest that LLSVPs are primordial, which suggests the LLSVPs cannot be purely thermal anomalies. To explain why the LLSVPs have remained at the base of the mantle for billions of years, they must have higher intrinsic density that the ambient mantle in addition to being hot, but this is still debated. To contribute to understanding whether LLSVPs are intrinsically dense, chemically distinct piles versus purely thermal, we compare the velocity of ambient mantle flow, which may advect plume sources over LLSVPs, with surface hotspot motions. Results show that the largescale differences in surface hotspot motions are reproduced only when LLSVPs behave like topography that deflects ambient mantle flow. Because LLSVPs would only behave like topography that deflects ambient mantle flow if they are denser than ambient mantle material, our results provide additional evidence in support of LLSVPs as dense thermochemical piles. Key Points: Pacific hotspot motions are on average two times faster than Indo‐Atlantic hotspots in commonly used reference framesThe contrast in mean hotspot speed is reproduced in the models only if Large Low‐Shear‐Velocity Provinces (LLSVPs) behave like topography that plume sources are advected overLLSVPs would behave like topography that plume sources are advected over only if they are denser than ambient mantle material [ABSTRACT FROM AUTHOR]