The Ir(111)/SiC(111) interfaces were investigated by first-principles study based on density functional theory (DFT). Considering different stacking sites and terminations, six different interfaces were studied. The results show that an Ir(111) slab with 9 atom layers exhibits bulk-like interior characteristic, while a 12-atom-layer SiC(111) slab represents the properties of bulk SiC. Adhesion and interfacial energy results show that the C-terminated top-site (C-TS) and Si-terminated center-site (Si-CS) interfaces are highly stable with the highest work of adhesion of 6.35 and 6.23 J/m², and the smallest interfacial energy of 0.07 and 0.10 J/m² after relaxation, respectively. Electronic structure analysis reveals that the C-TS interface has the ionic characteristics, while the Si-CS interface exhibits covalent bond characteristics. The bonding strength and stability of C-TS and Si-CS interfaces are attributed to the hybridization between Ir-d and C-p, Si-p orbits. Compared with the C-TS interface, sub-interfacial atoms have more interaction with Ir atoms in Si-CS interface.