From the reaction of a high-valent Sb(V) proligand with a low-valent Ir(I) precursor in acetonitrile, a bimetallic Sb–Ir complex was isolated in which one of the quinoline groups inverted such that it is N-coordinated to Sb and C-coordinated to Ir. The new Sb–Ir complex has a unique structure containing the shortest reported Sb–Ir bond (2.51502(18) Å). Our combined experimental and computational studies indicate pronounced covalent character for the Sb–Ir bond. Based on the covalent bonding, the complex more closely resembles Sb(IV)–Ir(II) species rather than Sb(V)–Ir(I) and thus results in an Ir center with poor π-basicity, particularly toward the position trans to Sb.