The International Symposium on Dielectric Materials and Applications (ISyDMA) provides a global platform for researchers to exchange ideas, present findings, and discuss advances in dielectric materials and their applications. The ISyDMA Proceedings document cutting-edge research on topics such as high-? dielectrics, electrical insulation, dielectric phenomena, and emerging uses in biomedical technologies, energy harvesting, smart materials, and critical infrastructure. The ninth edition, ISyDMA?9, was hosted by Cadi Ayyad University, Marrakesh, Morocco, from May 7?9, 2025. This volume compiles peer-reviewed papers presented at the conference, beginning with keynote contributions offering broad perspectives on mechanisms, processes, and applications of dielectric materials, followed by original research articles. Highlights include studies on the structural self-organization of chalcogenide glasses and their effect on low-frequency Raman scattering. Research on parametric optimization for IoT energy harvesting shows how modeling reduces trial-and-error in fabrication. Other contributions explore microplasma-sprayed hydroxyapatite coatings for enhanced bioactivity in 3D-printed implants, dielectric barrier discharge techniques to mitigate microplastics, and photoacoustic methods for measuring optical absorption in nanostructured silicon. Further studies examine DC conductivity in polypyrrole composites, synthesis and dielectric properties of high-purity NiMoO? nanospheres, and theoretical insights into metal carbides and nitrides for advanced electronic applications. Several papers demonstrate that moderate doping improves electrochemical performance, highlighting dielectrics? potential in next-generation energy storage. Notably, Poly(vinylidene fluoride) membranes modified with styrene?butadiene rubber and graphene nanosheets exhibit ?-phase-rich structures with tunable conductivity, ideal for piezoelectric energy harvesting. Additional articles address AI integration into energy management and the development of high-efficiency photodetectors using optically transparent dielectric materials for hazardous substance monitoring. Student contributions showcase innovative aspects of dielectric science and its interdisciplinary applications. This collection serves materials scientists, physicists, chemists, biologists, and electrical engineers engaged in fundamental and applied research on dielectric materials and their technological impact.