The goal of the present paper is to provide experimental validation data for the aeroelastic analysis of composite aeroelastically tailored wings with a closed-cell cross-sectional structure. Several rectangular wings with different skin thicknesses and composite layups are designed in order to minimize the root bending moment under maneuver loading using an aeroelastic analysis framework that closely couples a geometrically nonlinear beam model to a vortex lattice aerodynamic model. The globally convergent method of moving asymptotes is used to derive an optimized layup for the tailored wings. In addition, a quasi-isotropic wing is analyzed to serve as a reference. Both the tailored wings and the quasi-isotropic wing are manufactured and tested structurally and in the wind tunnel. In the wind tunnel, aerodynamic forces and moments and wing deformation are measured to provide experimental validation data.