Radio Frequency Identification (RFID) technology, capable of wirelessly processing large amounts of information, is gaining attention with the advancement of IoT technology. RFID systems can be utilized as Wireless Sensor Network (WSN) technology by introducing sensing materials responsive to external environmental stimuli. To achieve effective information communication and sensing capabilities, various types of nanomaterials are being used as various components of RFID sensors. This paper provides an overview of the RFID sensor system and the nanomaterials used in their composition. Polymers that can achieve flexibility are attracting more attention as user-friendly substrates as demand for them increases in the wearable market. Additionally, advancements in inkjet printing technology, allowing cost-effective and simple production of components, introduce inks and manufacturing methods utilizing various nanomaterials such as metal nanoparticles, carbon materials, and composites. Furthermore, nanomaterials utilized as sensing materials enable the detection of various external environments with high sensitivity and a wide detection range. Consequently, RFID sensor systems that achieve wireless detection in a variety of environments are actively utilized in many applications. By analyzing the current research progress and problems faced in RFID sensor technology, this paper suggests future research directions for its development as a next-generation wireless sensor system.