In this work, we investigated the crystal and electronic structure of ZnSb 2 O 6 with hybrid density functional theory, and validated this description with quasi-particle self-consistent GW theory (Green's function, G with a screened Coulomb interaction, W ). A full intrinsic defect analysis was performed that showed when nominally undoped, ZnSb 2 O 6 does not fulfil the Mott criterion for metallic-like conductivity. We then considered three extrinsic dopants, and demonstrated that Ga is the optimum electron donor in ZnSb 2 O 6 . Using this knowledge, we successfully grew powder and single crystal samples of Ga-doped ZnSb 2 O 6 , which displayed excellent optical transparency and a low absorption coefficient (88 cm -1 ) in the visible range, electron mobility up to 49 cm 2 V -1 s -1 , conductivity up to 1890 S cm -1 , carrier concentrations on the order of 2 × 10 20 cm -3 , and a Haacke figure of merit comparable with polycrystalline ITO. We found the electron affinity of ZnSb 2 O 6 to be nearly 1 eV larger than currently available transparent electrodes, offering much needed diversity when considering the band alignment of potential contact layers in devices. Ga-doped ZnSb 2 O 6 displays all the indicators of a high-performance transparent conductor, and this study stands as an important proof-of-concept for Sb(V) based TCO design.