Brain-Computer Interfaces (BCIs) have emerged as revolutionary technologies in neuroscience, providing bidirectional communication between the brain and external devices. However, the development of BCIs faces significant challenges, particularly in creating sensitive and biocompatible interfaces. Recently, conductive polymers (CPs) and hydrogels have attracted many attentions due to their unique properties in addressing these challenges. In this chapter, we provide an overview on CPs and hydrogels, discussing their different synthesis methods and properties required for neural interfacing applications. Also, we highlight the synergy of CPs and hydrogels in composite and hybrid systems for improving the performance of neural interfaces. Afterwards, we delve into their various applications, including signal recording and stimulation devices, tissue engineering and neural regeneration, smart drug delivery, artificial synapses and muscles, molecular bioelectronics, and biodegradable implants. Finally, we mention the main challenges for fabrication of high-performance BCIs based on CPs and hydrogels, and conclude with insights in future directions, emphasizing the essential strategies to overcome the current limitations and unlock the full potentials of these materials in advancing the BCIs.