Dye-sensitized solar cells (DSSCs) are a promising renewable energy technology, and the development of high-performance sensitizer dyes is key to improving their power conversion efficiency. This work utilized synthesis and theoretical studies to investigate ten new hydrazonoyl cyanide-based organic dyes (AML-1-4) as photosensitizers for DSSC applications. The effects of systematic variations in the donor, π-spacer, and acceptor/anchoring units on optical, electronic, and photovoltaic properties were analyzed. The absorption spectra, frontier molecular orbital distributions, intramolecular charge transfer characteristics, light-harvesting efficiency (LHE), injection driving force (ΔGinject), dye regeneration (ΔGreg), recombination driving force (∆Grec), and open-circuit voltage (VOC) were calculated. Among the proposed dyes, AML-4, which contains a carbazole as a strong donor and a chlorohydrazonoyl cyanide acceptor, demonstrated the most red-shifted absorption, narrowest bandgap (1.90 eV), superior electron delocalization, most favorable alignment of frontier orbital energies for efficient electron transfer processes, and greater GInject and GReg values compared to the other sensitizers. Comprehensive simulations provide an in-depth understanding of structure-function relationships to advance molecular engineering strategies for developing optimal hydrazonoyl cyanide-based organic photosensitizers. This study lays the theoretical foundation for the experimental realization of high-performance dyes tailored through judicious structural modifications.