A simplified procedure is presented for the design of a leading-edge fairing of a wing-body combination. The design aims at optimizing the design of the fairing, which is to serve the double purpose of eliminating separation near the wing-body junction, as well as minimizing leading-edge contamination of the laminar wing. The design optimization procedure is based on the analysis of the viscous-flow performance of a fairing of prescribed geometry. First, a panel method is used to determine the inviscid flow around the fairing. This is then followed by an integralmethod calculation of the boundary-layer development on the attachment line along the body and the fairing. As an application, a fairing was designed for a straight NACA0015 wing mounted on a flat plate. Tests in the wind tunnel confirmed the effectiveness of the fairing. NomenclatureH , H 1 = boundary-layer shape factors Re = Reynolds number r = crossflow model switching parameter U e , W e = external flow velocity components U ∞ = freestream velocity u, v, w = velocity components x, y, z = Cartesian coordinates δ = boundary-layer thickness δ * = displacement thickness θ = momentum thickness µ, µ T = dynamic viscosity; turbulent viscosity ν = kinematic viscosity, µ/ρ ρ = density τ = shear stress