Recently, solid-state electrolytes have been a highly active area of research for future Li-ion batteries due to the potential for drastically improved energy density and safety. Among these materials, garnet structured lithium lanthanum zirconate (Li₇La₃Zr₂O₁₂, LLZO) shows particular promise owing to the high ionic conductivity of its cubic polymorph, inertness, and electrochemical stability against metallic lithium. Herein we report the facile preparation of phase-pure cubic LLZO via molten salt synthesis at temperatures substantially lower than conventional solid-state reactions. Fine powders of cubic LLZO were obtained with primary particle sizes in the submicron range. Depending on the consolidation conditions, dense ceramics with Li⁺ conductivity values above 0.371 mS cm^-1 could be obtained. It is also observed that the effect of hydration has a profoundly deleterious effect on sintering and densification, and that this effect can be mitigated by the simple addition of LiOH before sintering to reverse hydration and aid densification. Qualitative discussions on the mechanisms of LLZO formation in the molten salt medium are discussed, in addition to implications for future scalable processing of LLZO electrolytes.