Abstract In recent times, the quickly mounting global economy has caused severe environmental problems and excessive utilization of fossil fuels, resulting in important threats to the survival and development of humankind. For that reason, employing sustainable and clean energy in addition to efficient energy conversion and storage technologies is immediately required. It was approximated that the world will require doubling its energy supply by 2050. For this reason, advanced technologies for both energy storage (supercapacitors and batteries) and conversion (solar cell and fuel cell) are being widely studied around the world. Over the last few decades numerous researches are going on the field of carbon nanotubes (CNT) and conducting polymer-based nanocomposites as well as graphene and conducting polymer–based nanocomposites for energy storage applications. The present chapter gives a brief overview of the most recent research on CNT and graphene-based hybrid nanocomposites for electrochemical supercapacitors.