Single-crystal X-ray diffraction studies of two polyaromatic radical anions crystallized as sodium salts, namely [Na(DME)3]+[C20H10−] (1) and [Na(DME)3]+[C24H12−] (2) are reported. This allowed the first structural evaluation of Jahn–Teller (JT) effects for monoreduced circulenes and a comparison between bowl-shaped corannulene and planar coronene. The Cs and D2h symmetrical distortions are found to fit the experimental data for C20H10.− and C24H12.−, respectively. The continuous symmetry measure (CSM) analysis was carried out to provide a quantitative measure of the JT distortions in 1 and 2. In addition, the X-ray crystallographic results were fully supported by DFT calculations.