AlGaN/GaN devices have shown outstanding potential for power conversion applications. However, despite the recent progress, their performance is still far from what the material can offer in terms of on-resistance and breakdown voltage. To address this challenge, here we demonstrate a multi-channel tri-gate High-Electron-Mobility Transistor (HEMT) based on an AlGaN/GaN multiple channel heterostructure and a nanostructured gate region. The multi-channel heterostructure leads to a significantly reduced sheet resistance while the nanostructured gate provides excellent control over all the embedded channels and enables to effectively manage the large off-state electric fields. This approach results in e-mode devices with a threshold voltage (V TH ) of 0.85 V at 1 μA/mm very low specific on-resistance of 0.46 mOhm•cm 2 , and a large breakdown voltage of 1300 V. In addition, we demonstrate multi-channel devices with excellent V TH stability and reduced current collapse thanks to a novel conformal passivation technique, which shows the potential of the multi-channel tri-gate technology for future power conversion applications.