In this letter, we present high-performance GaN-on-Si metal-oxide-semiconductor high electron mobility transistors with record reverse-blocking (RB) capability. By replacing the conventional ohmic drain with a hybrid tri-anode Schottky drain, a high reverse breakdown voltage ( ${V}_{\text {B}}^{\text {R}}$ ) of −900 V was achieved (at $1~\mu \text{A}$ /mm with grounded substrate), along with a small reverse leakage current ( ${I}_{\text {R}}$ ) of ~20 nA/mm at −750 V. The devices also presented a small turn- on voltage ( ${V}_{{ \mathrm{\scriptscriptstyle ON}}}$ ) of 0.58 ± 0.02 V, a small increase in forward voltage ( $\Delta {V}_{\text {F}}$ ) of ~0.8 V, a high ON/OFF ratio over 1010, and a high forward breakdown voltage ( ${V}_{{{\text {B}}}}^{{{\text {F}}}}$ ) of 800 V at 20 nA/mm with grounded substrate. These results demonstrate a new milestone for RB GaN transistors, and open enormous opportunities for integrated GaN power devices.