Zinc oxide (ZnO) single crystal was grown, for the first time, by the self-flux method using a high-purity zinc solvent saturated with oxygen. ZnO crystals were successfully grown in the solvent by moving a growing crystal slowly, at about 17mm/day along a temperature gradient (1.5°C/mm) in a furnace, from 1050 to 500°C. Hexagonal single crystals 1–3mm in length and 0.5–1mm in thickness were obtained. Energy-dispersive X-ray diffraction, secondary ion mass spectrometry, and photoluminescence confirmed that the purity and crystallinity of the ZnO crystals grown in this work were high.