Transparent Ce3+ and Gd3+ co-doped Y3Al5O12 (Ce,Gd:YAG) single crystal (SC) was successfully grown by the Czochralski method. Meanwhile, the structures and optical properties of single crystal wafers (SCWs) were investigated. When Y3+ ions were partially substituted by Gd3+ ions, the emission peak shifted towards the long wavelength direction. Compared with commercial phosphors, SCWs not only showed excellent thermal stability, but also exhibited superior optical performance with a luminous efficacy of 144.11lm/W, a correlated color temperature of 5639K and a color rendering index of 69.9.