Field‐effect transistor‐based biosensors (FET biosensors) have gained significant attention in the context of the global SARS‐CoV‐2 pandemic owing to their label free and highly sensitive detection capabilities. In this comprehensive review, recent advances in the use of electrochemical‐transistor‐based biosensors for the label‐free detection of SARS‐CoV‐2 are analyzed. A general introduction to the electrochemical‐transistor‐based biosensor system is initiated, highlighting its critical technical requirements. Various structural designs and working principles of transistor‐based transducers are described, and the essential aspects of interface engineering for improved sensing performance are summarized. The applications of transistor‐based biosensors for the detection of SARS‐CoV‐2 are discussed in detail. Finally, perspectives for the future development of transistor‐based sensing systems are provided. This review aims to provide valuable insights and guidance for the design and optimization of biochemical sensor systems with the potential to impact health monitoring, disease diagnosis, and biosafety in the field of in vitro diagnostic products.