The increasing demand for clean and renewable energy sources has led to the exploration of hydrogen as a sustainable energy carrier due to its high energy content and eco-friendly by-products. However, traditional hydrogen production methods face environmental and energy efficiency challenges due to their reliance on fossil fuels. Biomass, recognized as a carbon-neutral and versatile energy source, offers a sustainable alternative to hydrogen production. Microalgae emerge as a promising candidate among biomass options due to their high growth rates, minimal land requirements, and adaptability to different environments. Microalgae can produce biohydrogen under specific physiological conditions, making them a key focus for renewable hydrogen production. Therefore, this chapter provides an overview of biohydrogen production from microalgae, examining their characteristics, cultivation systems, metabolic pathways, and recent advances in improving hydrogen yields. Additionally, it explores biomass harvesting techniques, processing methods, and future perspectives for the large-scale application of microalgae in sustainable biohydrogen production.