Organic and perovskite solar cells are attractive solar technologies that particularly suitable for flexible and wearable applications because of the printing ability and mechanical softness of the active materials. One key challenge in the realization of these potentially low-cost flexible photovoltaic devices is how to print high-quality transparent and opaque electrodes with good flexibility. Transparent electrodes in current photovoltaics are transparent conductive oxides (TCOs), which are fragile to bending. Opaque electrodes, on the other hand, are made of metals that are difficult to print in high quality. Recently, our research group has developed printable TCO-free transparent electrodes and printable metal electrodes, which possess low resistance, high optical properties, good flexibility, and good smoothness. This talk will discuss the materials and fabrication of these electrodes and the applications on flexible organic, perovskite, and tandem solar cells.