A ribosome display from a diverse random library was applied for selecting peptide aptamers with high binding affinity to single-wall carbon nanotubes (SWCNTs). The selected peptide aptamer bound to and solubilized SWCNTs more strongly than did the peptide aptamer selected by a phage display method reported previously, and more strongly than other commonly used organic surfactants. The fluorescence spectrum of this aptamer showed a red shift upon interaction with SWCNTs but circular dichroism spectroscopy did not show any significant difference between the presence or absence of SWCNT binding.