During 2013, a novel equine-like G3P rotavirus emerged as the dominant strain in Australian children with severe rotavirus gastroenteritis. Full genome analysis demonstrated that the strain was an inter-genogroup reassortant, containing an equine-like G3 VP7, a P VP4 and a genogroup 2 backbone I2-R2-C2-M2-A2-N2-T2-E2-H2. The genome constellation of the equine-like G3P was distinct to Australian and global G3P strains. Phylogenetic analysis demonstrated a genetic relationship to multiple gene segments of Japanese strains RVA/JPN/S13-30/2013/G3P and RVA/Human-wt/JPN/HC12016/2012/G1P. The Australian equine-like G3P strain displayed a distinct VP7 antigenic profile when compared with the previously circulating Australian G3P strains. Identification of similar genes in strains from several geographical regions suggested the equine-like G3P strain was derived by multiple reassortment events between globally co-circulating strains from both human and animal sources. This study reinforces the dynamic nature of rotavirus strains and illustrates the potential for novel human/animal reassortant strains to emerge within the human population.