Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) is increasingly being used in the field of printed and flexible electronics in the form of electrode as well as intermediate layer. PEDOT:PSS belongs to the family of intrinsically conducting polymer materials whose members can conduct electricity in spite of their organic nature without the presence of metals. It is non-toxic, stable in the presence of air and humidity. Above all, it can be easily processed through conventional means. This chapter deals with the applications of PEDOT:PSS in organic solar cells (OSCs), dye sensitized solar cells (DSSCs) and silicon based hybrid solar cells. PEDOT:PSS is being used as electrode, buffer layer and hole conductive layer. It could manipulate the catalytic nature of counter electrode used in DSSCs. Whereas it may help to manipulate the morphological character in Si based hybrid solar cells along with enhancement of cell performance.