Recently, gallium nitride (GaN) films grown on graphene have been widely studied. Here, we have grown low-threading-dislocation-density GaN films on graphene by hydride vapor phase epitaxy (HVPE). The full widths at half maximum (FWHMs) of X-ray rocking curves (XRCs) of the GaN films were 276 and 350 arcsec at the 0002 and reflections, respectively. This shows that the threading dislocation densities are on the order of magnitude of 108 cm−2, which is consistent with the results of cathodoluminescence (CL).