In this paper, a fast transient response capacitor-less gallium nitride (GaN)-based LDO on the GaN smart power technology platform for GaN integrated power regulation application is first proposed. A proposed GaN error amplifier (EA) with bootstrapping technology can effectively boost the gain to 45 dB. By employing the EA and a regulator enhancement-mode HEMT, the LDO is able to achieve a 22 MHz unit gain frequency with a load capacitor and current ranging from 0 pF to10 pF and 250 μA to 100mA, respectively. And the short settling time (20 ns) for 50–100 mA load change in 10 ns edge-time without load capacitor manifests superior high-frequency performance compared to silicon-based LDO. The circuit further promotes the development of an all-GaN solution compact power management system with improved reliability and performance.