Rare‐earth (RE) doped zinc oxides (ZnO) are regarded as promising materials for application in versatile color‐tuned devices. However, the understanding of underlying luminescence mechanism and the rule of 4 f‐related electronic transition is still limited, which is full of significance for the exploration of advanced RE‐based ZnO phosphors. Thus, a series of ZnO : RE (RE=Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb) phosphors have been investigated by means of first‐principles calculations. Meanwhile, we also consider the effect of native defects (VO, VZn) on the luminescence of ZnO : RE phosphors. Accordingly, four types of electric‐dipole allowed transition processes are figured out in ZnO : RE family. Additionally, we manifest that the VO can further improve the luminescent performance of ZnO : RE phosphors, and give insightful guidance to design desired RE‐based ZnO materials with excellent luminescence.