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Abstract Above‐bandgap femtosecond optical excitation of a ferroelectric/dielectric BaTiO₃/CaTiO₃superlattice leads to structural responses that are a consequence of the screening of the strong electrostatic coupling between the component layers. Time‐resolved X‐ray free‐electron laser diffraction shows that the structural response to optical excitation includes a net lattice expansion of the superlattice consistent with depolarization‐field screening driven by the photoexcited charge carriers. The depolarization‐field‐screening‐driven expansion is separate from a photoacoustic pulse launched from the bottom electrode on which the superlattice is epitaxially grown. The distribution of diffracted intensity of superlattice X‐ray reflections indicates that the depolarization‐field‐screening‐induced strain includes a photoinduced expansion in the ferroelectric BaTiO₃and a contraction in CaTiO₃. The magnitude of expansion in BaTiO₃layers is larger than the contraction in CaTiO₃. The difference in the magnitude of depolarization‐field‐screening‐driven strain in the BaTiO₃and CaTiO₃components can arise from the contribution of the oxygen octahedral rotation patterns at the BaTiO₃/CaTiO₃interfaces to the polarization of CaTiO₃. The depolarization‐field‐screening‐driven polarization reduction in the CaTiO₃layers points to a new direction for the manipulation of polarization in the component layers of a strongly coupled ferroelectric/dielectric superlattice.