Metalorganic chemical vapor deposition (MOCVD) was used to grow crystalline GaN on a Ga2O3 interlayer deposited by pulsed laser deposition. The Ga2O3 interlayer situated between undoped GaN (u-GaN) and sapphire can be etched out during the chemical lift-off process. A (201) oriented -Ga2O3 thin film was first deposited on the sapphire; this was followed by u-GaN growth via MOCVD carried out in an N2 atmosphere to prevent the decomposition of Ga2O 3. Using transmission electron microscopy (TEM), the orientation relationship was observed to be GaN1120Ga2O3010 where the lattice mismatch between the two materials was 8.5. The full width at half maximums of the x-ray rocking curve at the GaN (0002) plane and of the photoluminescence spectrum measured from GaNGa2O3sapphire were 1444 arcsec and 8.3 nm, respectively; these were almost identical to the measured values for GaNsapphire fabricated in an N2 environment. It was concluded that the growth atmosphere played a more important role in determining the crystallinity of u-GaN than the Ga2O3 thin film underneath. Finally, an InGaN light-emitting diode structure was successfully fabricated on the GaNGa2O3sapphire.