An acoustic shear surface wave can be guided by the interface between two semi‐infinite media in contact across a planar interface, if at least one of the two media is magnetoelastic. The dispersion relation for such a wave is obtained in the case that it propagates in a direction normal to the direction of the spontaneous magnetization in each medium, which is assumed to be parallel to the interface. A solution of the dispersion relation is obtained analytically for a particular simple case.