AbstractDielectric and thermal characterization of nanohybrid films based on poly(ε‐caprolactone) biopolymer were investigated. Nano‐composites samples with distinct loadings of halloysite nanotubes (HNT) were prepared by in situ Ring Opening Polymerisation of ε‐caprolactone. The effect of the incorporated HNT on the molecular relaxation process and interfacial polarization of PCL was studied via broadband dielectric spectroscopy (BDS) on a frequency domain starting from 1E‐1 to 1E6 Hz and at temperatures ranging from −70°C to 50°C. The BDS measurements revealed four significant dielectric processes α‐primary relaxation attributed to glass transition,β‐secondary relaxation and two interfacial polarizations due to the semi‐crystalline character of PCL and the added HNT fillers. According to our results, the weight ratio of HNT ranging between 3% and 5% is recommended for achieving the highest performing nanocomposite that can be used in several applications.