This study investigates the synthesis and application of composite electrospun fibers incorporating coal tar pitch (CTP) and various nanomaterial additives, with a specific focus on their potential for eco-bio-applications. The research underscores the environmentally viable aspects of CTP following a thermal treatment process that eliminates volatile components and sulfur, rendering it amenable for fiber electrospinning and subsequent carbonization. Composite fibers were fabricated by integrating CTP with nanomaterials, including nickel oxide (NiO), titanium dioxide (TiO2), activated carbon (AC), and magnetite (Fe3O4). The C/NiO composite fibers exhibit notable acetone sensing capabilities, specifically displaying a rapid response time of 40.6 s to 100 ppm acetone at 220 °C. The C/TiO2 composite fibers exhibit a distinct “beads-on-a-string” structure and demonstrate a high efficiency of 96.13% in methylene blue decomposition, highlighting their potential for environmental remediation applications. Additionally, the C/AC composite fibers demonstrate effective adsorption properties, efficiently removing manganese (II) ions from aqueous solutions with an 88.62% efficiency, thereby suggesting their utility in water purification applications. This research employs an interdisciplinary approach by combining diverse methods, approaches, and materials, including the utilization of agricultural waste materials such as rice husks, to create composite materials with multifaceted applications. Beyond the immediate utility of the composite fibers, this study emphasizes the significance of deploying environmentally responsible materials and technologies to address pressing eco-bio-challenges.