A polarizing plate includes a base layer, a buffer layer and a plurality of conductive lattice lines. The buffer is formed on the base layer. The conductive lattice lines are formed on the buffer layer in a stripe shape to reflect and polarize incident light. The buffer layer protects the conductive lattice lines. The conductive lattice lines include a silver (Ag) layer or an aluminum (Al) layer. Therefore, the buffer layer protects the conductive lattice lines, so that the lifetime of the polarizing plate may be increased. Furthermore, the display quality of a display panel and a display device having the polarizing plate may be enhanced.