The success of (nano)materials and polymer composites lies in their ability to be tailored to each specific application. For the latter, with the right choice of the polymer and (nano)material, it is possible to obtain new electrical, thermal and mechanical properties different from those of pure polymers. Among all their properties, research into their dielectric properties is essential for their successful application in a wide range of applications, including capacitors, sensors, insulation cables and transmission lines, connectors, printed circuits, multichip modules, antennas, antistatic protection and encapsulation of electronic components, etc. Therefore, this Mini-colloquium aims to review the current state on the dielectric properties of nanomaterials and polymer composites, with the latest findings and their applications, as well as possible directions for future work. Specifically, their design, synthesis and sustainable development will be addressed, without forgetting their modified structural, mechanical and thermal properties, with the aim of generating multifunctional materials. The symposium will also highlight modelling and process optimisation techniques used to produce these innovative materials. The ultimate goal will be to foster the exchange of scientific and technical information between academic and industrial speakers. This exchange will illustrate the advantageous potential of nanomaterials and polymer composites and offer promising concepts for the development of new generation of electronic components.