The Lithosphere–Asthenosphere Boundary (LAB) is a fundamental boundary in the plate tectonic paradigm — it is the most pervasive on the planet, yet comparatively it is one we know little about. Defined initially on the basis of the mechanical response of the Earth to loading, its usage has become ubiquitous across the geosciences but the natural differences in its definition, due to differences in thermal, physical and chemical parameters, cause confusion. To advance this debate, comparisons are made both qualitatively and quantitatively, between the delineation of the LAB for Europe based on seismological and electromagnetic observations. We examine statistically, using robust methods, the LABs derived from independent datasets and methods.