Green hydrogen (H ₂ ) emerges as a sustainable alternative to fossil fuels, offering a clean method to store renewable energy through water electrolysis with high energy content and zero carbon emissions. While research largely focuses on specific aspects such as hydrogen evolution reaction (HER), seawater HER electrocatalysts, and electrolyzer development, these studies often overlook the broader hydrogen economy from an integrated industry chain perspective. This review bridges that gap by providing a comprehensive analysis of hydrogen energy industrialization, covering advancements in HER, seawater HER, and electrolyzers, all aim at enabling industrial‐scale H ₂ production. It further explores innovations and challenges in hydrogen storage and transportation, as well as real‐world projects spanning the green hydrogen supply chain. Additionally, life cycle assessment studies validate the environmental benefits of using renewable energy sources for green H ₂ production. Furthermore, this review highlights advancements in counter‐oxygen evolution reactions and organic oxidation reactions, alongside strategies to mitigate competing chlorine evolution reactions. Through this comprehensive examination, this review aims to inform readers of the latest developments in hydrogen energy industrialization, explore its growth potential, and provide new insights to propel the hydrogen economy forward.