<p>We solve the inverse problems in both three-dimensional and two-dimensional elasticity associated with the design of harmonic ellipsoidal and elliptical isotropic elastic inhomogeneities with spring-type imperfect interface. The first invariant of the stress tensor in the infinite isotropic elastic matrix subjected to uniform remote normal stresses remains unchanged after the introduction of the harmonic inhomogeneity. The jump in normal displacement across the interface is proportional, in terms of the corresponding three-variable or the two-variable imperfect interface function, to the normal traction; the interface does not sustain any shear traction. The three-dimensional inverse problem is solved via the use of a Newtonian potential and its two-dimensional counterpart via Muskhelishvili’s complex variable method. In order to achieve the harmonic condition, the two ratios of the remote normal stresses for the three-dimensional problem and the single ratio of the remote normal stresses for the two-dimensional problem are uniquely determined for given geometric and material parameters.</p>