Despite its adherence to Huckel’s rule, [10]annulene is thought to prefer nonaromatic, nonplanar structures. This seemingly reasonable conclusion is based on experimental studies carried out a quarter century ago, but the detailed nature of the [10]annulene isomers has not been fully elucidated. A new, nearly planar aromatic mono-trans [10]annulene configuration has now been characterized at the second-order perturbation (MP2) and density functional (B3LYP) levels of theory. The structure, with a symmetry plane that bisects the molecule, is not a stationary point at uncorrelated levels, but it is the most stable [10]annulene isomer at MP2(fc)/DZd and at higher levels. The inner hydrogen is only bent out of the approximate carbon plane by about 20 degrees. The estimated aromatic stabilization energy (17.7 kcal/mol, after correction for strain), the diamagnetic susceptibility exaltation (Lambda = -66.9 ppm egg, Lambda(Naphtalene) = -28.2), and the upfield NMR chemical shift of the inner hydrogen (delta = -6.1 ppm) confirm the aromaticity of this new C-s [10]annulene conformation.