Shear-wave splitting observed in three-component broadband recordings of local earthquakes near southern Vancouver Island, British Columbia, provide the first constraints on shear-wave anisotropy in the continental crust above the subducting Juan de Fuca plate. Waveforms of 22 ''shallow'' earthquakes (15--30 km depth) and 16 ''deep'' earthquakes (40--60 km depth) were examined for shear-wave splitting. The fast-polarization direction is well-defined at 312¿19¿ for the deep earthquakes, and 293¿27¿ for the shallow earthquakes. These fast polarization directions are approximately parallel to the continental margin and coincide with the orientation of the pressure axes of small crustal earthquakes in this region. Interpreting this polarization pattern in terms of the extensive-dilatancy anisotropy model indicates a margin-parallel compressive stress regime. Comparing the average time delays between the fast and slow shear-waves for the deep earthquakes (0.32 s) and the shallow earthquakes (0.20 s) suggests that the source of the seismic anisotropy is stronger in the upper 20 km of the continental crust. Here, the average differential shear-wave anisotropy is estimated at 2.3%. These observations support the theory of weak coupling between the downgoing Juan de Fuca plate and the overlying North America plate, as the principal stress is perpendicular to the direction of subduction, and the S-wave splitting above the subducting plate is nearly perpendicular to the SKS splitting direction in the upper mantle beneath the subducting plate. ¿ American Geophysical Union 1996