<p>This study investigates the synthesis and characterization of zirconium-doped calcium titanate (CaTi_1-xZr_xO₃​) perovskites using seashell-derived calcium carbonate as a sustainable source of calcium. The seashell powder, primarily composed of aragonite, was analyzed via X-ray fluorescence (XRF) and X-ray diffraction (XRD) techniques. The perovskite materials were successfully synthesized via solid-state reaction and characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Raman spectroscopy, scanning electron microscopy (SEM), UV–Vis spectroscopy, and dielectric measurements. XRD analysis revealed the phase separation and the coexistence of two perovskite-type phases a CaTiO₃-rich phase and a CaZrO₃-rich phase across the Zr⁴⁺ doping. The structural modifications have been confirmed via both FTIR and Raman spectroscopies. Morphological studies via SEM showed homogeneous, agglomerated grains with decreasing size (178–140 nm) as Zr doping increased, suggesting inhibited grain growth due to lattice strain and nucleation effects. EDX confirmed stoichiometric composition without impurities, affirming the robustness of the synthesis protocol. Optical studies indicated tunable band gaps and dielectric measurements demonstrated frequency-dependent polarization behavior. The results highlight the potential of waste-derived calcium for sustainable material synthesis and the influence of Zr doping on structural, optical, and electrical properties for applications in sensors and electronic devices. The conductivity analysis highlighted a transition in the dominant transport mechanism: correlated barrier hopping (CBH) for x = 0.0 to overlapping large polaron tunneling (OLPT) for x = 0.0, 0.2, 0.6 and 0.8, shifting in accordance with Jonscher’s universal power law.</p>