Abstract The annealing temperature dependence of contact resistance and layer stability of ZrB 2 /Ti/Au and Ni/Au/ZrB 2 /Ti/Au Ohmic contacts on p-GaN is reported. The as-deposited contacts are rectifying and transition to Ohmic behavior for annealing at ≥750 °C, a significant improvement in thermal stability compared to the conventional Ni/Au Ohmic contact on p-GaN, which is stable only to −3 Ω cm −2 was obtained for the ZrB 2 /Ti/Au after annealing at 800 °C while for Ni/Au/ZrB 2 /Ti/Au the minimum value was 10 −4 Ω cm −2 at 900 °C. Auger Electron Spectroscopy profiling showed significant Ti, Ni and Zr out diffusion at 750 °C in the Ni/Au/ZrB 2 /Ti/Au while the Ti and Zr intermix at 900 °C in the ZrB 2 /Ti/Au. These boride-based contacts show promise for contacts to p-GaN in high temperature applications.