This study explores the environmental and energy benefits of producing hydrogen (H2) through in-situ combustion gasification (ISCG), with an emphasis on minimizing carbon emissions and improving resource utilization. ISCG offers a promising pathway for sustainable H2 production. To evaluate its performance, a validated 1D combustion tube model was used to examine how oxidizer composition, cyclic steam injection and flame speed influence H2 generation, and oil recovery. The research compared two oxidizer systems, oxygen/nitrogen (O₂/N₂) and oxygen/carbon dioxide (O₂/CO₂). Results show that oxidizer composition strongly affects combustion behavior and H2 production. High-oxygen mixtures, such as 90% O₂ with either N₂ or CO₂, produced elevated peak temperatures that enhanced thermal cracking reactions, leading to increased H2 yields. Moderate oxygen contents, such as 60% O₂ blends, still generated substantial H2 but with lower combustion intensity, providing a balance between efficiency and operational control. In contrast, low-oxygen mixtures (34% O₂) produced lower peak temperatures, weaker combustion fronts, and reduced H2 output. Integrating CO₂ into the oxidizer was found to influence reaction pathways and carbon utilization. Thus, the use of O₂/CO₂ oxidizers provides both performance and environmental advantages. Cyclic steam injection was another key parameter affecting ISCG performance. Optimized steam injection improved H2 production, supported coke gasification, and helped regulate combustion front stability. However, excessive steam diluted the reaction zone and suppressed H2 generation, demonstrating the need for careful steam management. Overall, the findings highlight that strategic optimization of oxidizer composition and steam injection rates is essential for maximizing H2 production while minimizing environmental impacts. The addition of CO₂ to the oxidizer stream introduces opportunities for carbon utilization and reduced emissions, strengthening ISCG’s potential as a clean H2 technology. ISCG emerges as a viable method for low-carbon H2 production, enhanced oil recovery, and improved energy sustainability.