In recent decades, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS)-based polymeric materials have been extensively investigated as one of the most promising candidates for many organic electronics applications. PEDOT:PSS and its hybrids with inorganic nanostructural components potentially exhibit outstanding thermoelectric performance that is comparable to their traditional inorganic counterparts. In this review, we summarize the recent advances of PEDOT:PSS-based thermoelectric materials which are prepared via either hybridizing with a variety of inorganic nanomaterials and carbon nanostructures or facile post-treatment including solvent, vapour and electrochemical treatments. The thermoelectric properties of PEDOT:PSS-based hybrid materials in various environments are also reviewed, and the future research focuses, challenges and opportunities of this type of materials are addressed at the end.