AbstractA newly prepared tetraazulene‐fused tetracene diimide (TA‐fused TDI) showed absorption in the near‐IR region owing to the effective extension of the π‐conjugated system as well as a large two‐photon absorption cross‐section (σ(2)=2140 GM) at 950 nm. Four reversible reduction processes and n‐type semiconductivity were also confirmed as attractive electronic properties of this compound.