The piezo-optical properties of InP above the fundamental gap have been investigated. Uniaxial stress was applied along the [001] and [111] crystal directions and spectroscopic ellipsometry was used to determine the piezo-optical coefficients P11 , P12, and P44 in the energy range 1.6-5.5 eV at room temperature. Deformation potentials were determined for the E1 and E1 + Delta(1) transitions. Semiempirical tight-binding calculations of the piezo-optical coefficients and deformation potentials are in reasonable agreement with experiment.