This letter reports on extended defect density reduction in m-plane (1100) GaN films achieved via lateral epitaxial overgrowth (LEO) by hydride vapor phase epitaxy. Several dielectric mask patterns were used to produce 10 to 100 μm-thick, partially and fully coalesced nonpolar GaN films. X-ray rocking curves indicated the films were free of wing tilt. Transmission electron microscopy showed that basal plane stacking fault (SF) and threading dislocation (TD) densities decreased from 105cm-1 and 109cm-2, respectively, less than 3×103cm-1 and ∼5×106cm-2, respectively, in the Ga-face (0001) wing of the LEO films. SFs persisted in <0001>-oriented stripe LEO films, though TD reduction was observed in the windows and wings. Band-edge cathodoluminescence intensity increased 2 to 5 times in the wings compared to the windows depending on the stripe orientation. SFs in the low TD density wings of <0001>-stripe films did not appear to act as nonradiative recombination centers.