p‐type ZnO nanowires (NWs) based on a simple hydrothermal technique with a lithium dopant are demonstrated. It is demonstrated that Li substitution of Zn occurrs because of thermally induced migration due to post‐annealing in the presence of oxygen. The stable formation of p‐type ZnO:Li NWs is revealed using a NW field‐effect transistor and a simple n‐type ZnO thin film/p‐type annealed ZnO:Li NW homojunction diode.