The search for eco-responsible solutions is attracting the interest of end-use industries toward fiber-reinforced thermoplastic composites (FRT). However, numerous challenges are still limiting the development of efficient optimization approaches of FRT composites for structural parts. Such challenges emanate from complexities related to (i) the multiscale structure of reinforcement and (ii) multiphysical phenomena governing the use of thermoplastics within liquid resin transfer processes. In this context, the development of new interdisciplinary approaches for better understanding processing–structure–performance inter-relationships is encouraged to alleviate challenges related to (i) smart manufacturing, (ii) advanced microstructure characterization, (iii) numerical modeling of physical phenomena or (iv) simulation approaches. The current Special Issue aims to explore recent developments focused on FRT composites falling within the scope of the aforementioned topics. Multidisciplinary articles and review papers are encouraged to cover emerging topics such as artificial intelligence applied to manufacturing, data-driven simulations, multimodal microstructure characterization, hierarchical FRT composites, mechanical metamaterials, etc.