The rapid accumulation of food waste and the associated release of greenhouse gases have intensified the urgency to develop sustainable waste-to-energy strategies. Among renewable options, biohydrogen has emerged as a promising clean fuel due to its high energy density and zero-carbon emissions upon utilization. This review synthesizes recent advances in the optimization and integration of dark fermentation processes for biohydrogen production from food waste. Key considerations include substrate and inoculum selection, pretreatment methods, reactor configurations, and operational parameters such as pH, temperature, and retention time, all of which critically influence hydrogen yield and process stability. Current evidence highlights the effectiveness of carbohydrate-rich food residues combined with targeted thermal, chemical, and biological pretreatments in enhancing biodegradability and microbial activity. Similarly, inoculum pretreatment strategies selectively enrich hydrogenogenic consortia while suppressing methanogens, thereby stabilizing fermentation. Furthermore, integrated bioprocesses such as coupling dark fermentation with photo-fermentation, microbial electrolysis cells, lactic acid fermentation, or biomethane production have demonstrated significant improvements in energy recovery and system resilience. Computational approaches, including kinetic modeling, machine learning, and artificial intelligence, further enhance process predictability and scalability. Despite these advancements, challenges remain regarding substrate heterogeneity, economic feasibility, and large-scale stability. This review underscores the transformative potential of optimized and integrated dark fermentation systems, positioning biohydrogen production from food waste as a viable pathway toward sustainable energy transition and circular bioeconomy implementation.