New data are presented on the resonant Auger decay of iodobenzene (C₆H₅I) in the region of the I 4d⁻¹ ionization threshold. The excited molecules decay by participator and spectator processes to populate single-hole valence states and two-hole, one-particle excited states of the cation, providing new information on the structure of C₆H₅I⁺. Excitation of dissociative C₆H₅I (I 4d_5/2,3/2⁻¹)σ* resonances can, in principle, result in ultrafast dissociation to C₆H₅ + I** and the subsequent autoionization of I**, but no evidence for this process is observed. The results are compared with our recent study of the resonant Auger decay of methyl iodide (CH₃I).