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Motivated by Tilley et\u00a0al.\u2019s report of a key expanded helicene structure in 2017, several research groups have synthesized such nonplanar aromatic compounds, aiming to explore their impressive structures, properties, and chiroptical performance. This review highlights recent advances in the expanded helicene chemistry through experimental and theoretical studies. The shape and length of helical structures depend on the number and combination of angularly and linearly fused benzene rings. Helical structures are classified using notations, and specific compounds corresponding to each structural form, namely, hexagonal, triangular, rhombic, or others, are introduced herein. As an extension of the molecular design, examples of nonhexagonal and heteroaromatic ring\u2010embedded expanded helicenes are presented. 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