<p>Hückel’s (4<i>n</i> + 2) rule plays a vital role in rationalizing and predicting the aromaticity of annulenes (C_<i>n</i>H_<i>n</i>) and cyclic systems with delocalized electrons. The π-electron behavior in annulenes can be described by a two-dimensional (2D) jellium model, where π molecular orbitals (MOs) are treated as superatomic 2D orbitals (S, P, D …). Herein, heteroatoms (B, N, O) were introduced to replace C atoms in annulenes to extend the aromatic rule of monocyclic species beyond Hückel’s (4<i>n</i> + 2) framework. Electronic structures and aromaticity of C_<i>n</i>H_<i>n</i> (<i>n</i> = 4, 6, 8) and their heteroatom counterparts, B_<i>n</i>N_<i>n</i>H_2<i>n</i> and B_<i>n</i>O_<i>n</i>H_<i>n</i> (<i>n</i> = 2, 3, 4), were compared. C₆H₆, B₃N₃H_6, and B₃O₃H₃ with 6π electrons are aromatic with a superatomic closed-shell configuration of |S²|P⁴|, consistent with Hückel’s rule. Intriguingly, despite being 4<i>n</i> system, B₄N₄H₈/B₄O₄H₄ (8π) exhibit aromaticity, different from antiaromatic C₈H₈. Additionally, antiaromaticity of B₂N₂H₄/B₂O₂H₂ (4π) are weakened, exhibiting a new type of aromaticity. This is attributed to the significant splitting of the doubly degenerate superatomic P or D orbitals induced by the electronegativity difference between heteroatoms, which stabilizes the occupied orbitals (P_<i>x</i>, D_<i>xy</i>) relative to their unoccupied counterparts (P_<i>y</i>, D_<i>x2-y2</i>). This work enriches the fundamental understanding of aromaticity by proposing the 2<i>n</i>π (<i>n</i> ≥ 2) aromaticity in hetero-monocyclic molecules. </p> Graphical Abstract <p></p>