The global gas diffusion layer carbon paper market, valued at USD 647.1 million in 2024, is projected to reach USD 2,391 million by 2035, with a strong CAGR of 12.5%. Gas diffusion layer (GDL) carbon paper is essential in fuel cell technology, facilitating gas distribution, water management, and electrical conductivity. Market growth is attributed to the increasing adoption of fuel cells in automotive, stationary power, and portable electronics sectors. A significant driver of this growth is the expanding hydrogen economy and the rising use of fuel cell technology globally. Initiatives by governments to develop hydrogen infrastructure and promote clean energy are fostering a favorable market environment. The automotive industry, especially in commercial transportation, is witnessing growth due to the demand for fuel cell electric vehicles (FCEVs), necessitating high-performance GDL materials to support efficient energy conversion. Manufacturers face challenges such as high production costs and material complexity. The intricate manufacturing process demands precise control over properties like porosity, hydrophobicity, and electrical conductivity, along with strict quality control and testing procedures, leading to increased expenses. Achieving economies of scale is difficult for small-scale manufacturers, with raw material volatility adding to supply chain planning complexities. In the United States, the GDL carbon paper market is expected to reach USD 185.8 million by 2025, driven by investments in hydrogen fuel cell technology and supportive government initiatives. In China, the market is projected to reach USD 285.1 million by 2035, with aggressive clean energy targets and fuel cell deployment plans enhancing growth prospects. Key market players like Toray Industries Inc. are investing heavily in R&D to offer customized solutions and address industry challenges. A notable development includes Toray's expansion of production capacity for catalyst-coated membranes to meet increasing demand for hydrogen products. The market is segmented by material type, application, end-user, thickness, and region, reflecting the diverse applications and demand for GDL carbon paper.