Flexible electronics have attracted great attention due to their salient features and significant roles in the fields of energy, information, sensing, displays, smart skins, wearable systems, biomedical diagnostics, and artificial intelligence, etc. The past years have witnessed the rapid development of advanced materials and devices for flexible electronics. This special issue aims to collect high quality articles focused on thin-film materials, devices and carrier dynamics in flexible electronics and optoelectronics. It is desirable to search a variety of functional films including metallic, organic, inorganic, hybrid and composite materials for developing different types of flexible transistors, sensors, actuators, photodetectors, photovoltaic devices, light-emitting devices and beyond. It may contain, but not limited to material design, thin-film processing, structure regulation, property optimization, structure-property relationship, device engineering, and potential applications. Meanwhile, fundamental investigations on surface and interface characteristics, energy level alignments, charge and energy transfer processes, device operation mechanisms, and carrier dynamics related with advanced techniques such as ultrafast transient absorption and time-resolved (TR) spectroscopy, are welcome for understanding the thin-film materials and flexible devices. I kindly invite you to submit a manuscript(s) for this Special Issue. Full papers, communications, and reviews are all welcome.