Reducing vehicle weight is critical to improving fuel economy and addressing range, performance, size, and cost challenges associated with fuel-cell and hybrid propulsion systems. This paper describes the design, fabrication, and assembly approach used for the carbon-fiber composite body structure in Hypercar, Inc.’s Revolution concept vehicle. The Revolution’s 187-kg body structure is 57% lighter than a conventional steel body structure of the same size, while providing superior crash protection, improved stiffness, and favorable thermal and acoustic properties. The design balances several competing requirements, including surface finish, reparability, crash performance, weight, packaging constraints, and cost. A large part of the Revolution’s body structure is an advanced-composite passenger safety cell. Its design permits a novel high-volume manufacturing process under development by Hypercar. Applied together, the design and production method result in a lightweight, affordable advanced-composite body structure consistent with competitive vehicle cost at production volumes of 50,000 vehicles per year or greater. This paper describes the design and production method of the composite body, explains how the body is integrated with the rest of the vehicle, and analyzes the benefit of lightweighting on overall fuel-cell vehicle cost.