Two tin-based organic–inorganic hybrids, namely bis(3-cyanopyridinium) hexachlorostannate(IV) dihydrate (1) and bis(3-cyanopyridinium) hexabromostannate(IV) dihydrate (2), were synthesized and subjected to an extensive investigation to evaluate their crystal structures alongside their optical, third-order nonlinear, and dielectric responses. Single-crystal XRD study revealed that both hybrids contain discrete [SnCl<inf>6</inf>]2- and [SnBr<inf>6</inf>]2- anionic octahedral units, which are stabilized via extensive hydrogen-bonding interactions with 3-cyanopyridinium cations and interstitial water molecules. Compound (1) crystallized in the triclinic system with Pī symmetry, whereas compound (2) adopted a monoclinic structure with P2<inf>1</inf>/n space group. Diffuse reflectance measurements supported the proposed structural framework and indicated optical band gaps of 4.33 eV for (1) and 3.07 eV for (2), highlighting the halide-dependent modulation of electronic properties. Photoluminescence studies revealed near-UV emission for (1) and visible blue-green emission for (2), linked to halide identity. SEM–EDS and XRF analyses confirmed morphology and elemental composition. Z-scan measurements demonstrated third-order nonlinear susceptibilities of 8.48×10–11 esu for (1) and 7.01×10–11 esu for (2), highlighting their potential in photonics. Dielectric and AC conductivity analyses indicated relaxation behaviour consistent with thermally activated polarization and hopping-type carrier motion. Hirshfeld surface analysis emphasized the dominance of halogen-hydrogen and nitrogen-hydrogen interactions in crystal packing. These results demonstrate how halide substitution modulates the multifunctional behaviour of hybrid stannate frameworks, offering insights into their design for optical and electronic applications. © 2025