As the global energy sector shifts towards cleaner alternatives, underground hydrogen storage (UHS) emerges as a crucial element in the low-carbon hydrogen economy. While UHS offers a solution for managing renewable energy intermittency, successful implementation goes beyond identifying suitable pore spaces. The selection of optimal storage sites demands a comprehensive, multidisciplinary approach, considering factors like geochemical stability and geomechanical integrity. Recent studies broaden the understanding of nuanced variables affecting UHS performance, such as microbial activity, reservoir stress behavior, and hydrogen production potential from geological formations. The article highlights the challenges and opportunities in utilizing depleted oil and gas fields (DOGFs) and saline aquifers for UHS, emphasizing the influence of geochemical interactions and reservoir characteristics. Although there are engineering hurdles and gaps in geomechanical understanding, simulation-based studies show promising results for UHS feasibility in DOGFs. Furthermore, ongoing research delves into the geomechanical implications of UHS, indicating potential induced seismicity and stress changes in storage formations. Evaluations of hydrogen losses and recovery efficiency are critical for optimizing storage operations, with studies showing varying recovery factors depending on reservoir type and depth. Site-specific evaluations, like those in California's Sacramento Basin, aim to identify optimal storage conditions for maximizing withdrawal efficiency, underlining the importance of tailored approaches for real-world implementations. In conclusion, advancements in underground hydrogen storage present promising solutions for the transition to a sustainable energy future. While challenges persist, continued interdisciplinary efforts are crucial to enhance understanding, improve storage performance, and drive the successful integration of UHS in the global energy landscape.