Interface bonding between Pt and Zn- and O-terminated ZnO surfaces was investigated by precise analysis of x-ray photoelectron spectra. The interfaces were formed by vapor depositing Pt onto the ZnO surfaces in ultrahigh vacuum. The changes in the Zn 2p3/2, O 1s, Zn LMM Auger, and Pt 4f7/2 spectra upon Pt deposition were observed. The changes in the shape of the Zn LMM spectra and the shifts in the binding energy of Zn 2p3/2 and O 1s revealed that there was a metallic Zn component in the Zn LMM and Zn 2p3/2 spectra for Zn-terminated ZnO and a Pt-O component in the O 1s spectra for both Zn- and O-terminated ZnO. Peaks were fitted with multiple components accordingly. The binding energy shifts of Zn 2p3/2 and O 1s for the ZnO component were almost the same, which confirmed that the fitting was reasonable. From the fitting results, the interface bonding was concluded to be O-terminated, i.e., Zn-O-Pt bond formation occurred at the interface for both Zn- and O-terminated ZnO. This clearly demonstrated that the stable interface bonding occurring between Pt and ZnO is Zn-O-Pt bonding whether the ZnO substrate is initially Zn-terminated or O-terminated.