<p>The integration of conductive biological materials into in vitro models represents a transformative approach to advancing biomedical research while addressing critical sustainability challenges. Traditional materials used in tissue engineering and disease modeling are often environmentally detrimental, derived from non-renewable resources, and limited in their ability to replicate the dynamic properties of native tissues. Conductive biological materials bridge this gap by offering a unique combination of biodegradability, sustainability, and functional properties, such as bioelectricity and biocompatibility, that are essential for mimicking physiological environments. Herein, the development and current applications of biodegradable conductive materials, including advanced polymers such as polyaniline and polypyrrole, carbon-based nanocomposites, and renewable biopolymers derived from lignin and cellulose, are overviewed. These materials not only reduce the ecological footprint of biomedical research but also enable the precise simulation of electrical signaling in tissues, such as cardiac, neural, and muscular systems, thereby enhancing the physiological relevance of in vitro models. Their integration into three-dimensional (3D) tissue constructs, organ-on-chip platforms, and bioprinting technologies facilitates the development of patient-specific models, paving the way for personalized therapeutic and diagnostic applications. In addition to advancing biomedical precision, these materials align with global efforts to implement circular economy principles in research, promoting resource efficiency and waste reduction. By combining environmental responsibility with state-of-the-art functionality, conductive biological materials are redefining the future of in vitro 3D models and research, accelerating innovation in regenerative medicine, drug development, and disease modeling while fostering a sustainable framework for scientific discovery.</p>