Single-walled carbon nanotubes were incorporated into polyvinyl alcohol hydrogels by click chemistry, the Cu-catalyzed azide–alkyne cycloaddition reaction. This efficient and modular reaction allowed the production of hydrogels with cross-linker molecules of various properties such as hydrophilic or hydrophobic character. Control of cross-linking density and molecular transport inside the click hydrogels was demonstrated by measuring degrees of swelling and the electrochemical diffusion coefficient of an ionic solute. Incorporation of single-walled carbon nanotubes into the click hydrogels aided the growth of poly(3,4-ethylenedioxythiophene), presumably due to their enhancement of electrical conductivity.