Hydrogen is increasingly recognized as a cornerstone of sustainable energy systems, particularly for decarbonizing the transportation sector, which remains one of the largest global energy consumers. Owing to its high energy density, abundance, versatility in production pathways, and potential for zero or near-zero emissions when derived from renewable resources, hydrogen offers a compelling alternative to fossil fuels. This chapter provides a comprehensive assessment of hydrogen’s viability as a primary transportation fuel, with a specific focus on hydrogen-fueled internal combustion engines (ICEs). While fuel cell vehicles exhibit lower tailpipe emissions, their higher costs, additional weight, and space requirements limit near term adoption, making hydrogen ICEs a practical transitional solution. The chapter reviews recent literature to examine performance, efficiency, emissions, and system redesign requirements associated with hydrogen combustion. A comparative evaluation of conventional, hybrid, electric, biofuel, fuel cell, and hydrogen ICE vehicles is conducted using indicators such as CO₂ and SO₂ emissions, social cost of carbon, energy and exergy efficiencies, fuel consumption and cost, and driving range. The results indicate that fuel cell vehicles achieve the highest overall performance ranking, followed closely by hydrogen-fueled ICEs and biofuel vehicles, whereas conventional vehicles perform poorest. These findings highlight the strategic role of hydrogen-based propulsion, particularly hydrogen ICEs as an effective pathway toward cleaner, more efficient, and sustainable transportation systems.