Abstract The unique structure of carbon nanotubes (CNTs) endows them with exceptional electrical and mechanical properties, along with a high surface area, making them highly beneficial for use as flexible, high‐performing thermoelectric materials. As a result, the application of CNTs in the thermoelectric field has become increasingly widespread. Considering the rapid advancements in this field, this review offers a timely overview of the most recent progress on CNT‐based thermoelectric materials and devices over the past five years. This review begins by introducing the fundamental concepts and thermoelectric mechanisms of CNT‐based thermoelectric materials. Then new strategies are explored to enhance their thermoelectric performance, focusing on doping and composites, while emphasizing the importance of CNT stability as a key research area. Additionally, the latest design concepts and expanded application scenarios for flexible and wearable CNTs‐based thermoelectric devices are summarized. Finally, the current challenges are addressed and future directions for the development of CNT‐based thermoelectric materials and devices are discussed.