It is highly desirable to develop flexible and efficient energy‐storage systems for widely used wearable electronic products. To this end, fiber‐shaped lithium‐ion batteries (LIBs) attract increasing interest due to their combined superiorities of miniaturization, adaptability, and weavability, compared with conventional bulky and planar structures. Recent advances in the fabrication, structure, mechanism, and properties of fiber‐shaped LIBs are summarized here, with a focus on the electrode material. Remaining challenges and future directions are also highlighted to provide some useful insights from the viewpoint of practical applications. Fiber‐shaped lithium‐ion batteries represent a next‐generation, promising power source given the superiorities of miniaturization, adaptability, and weavability compared with their planar counterparts. Recent advances in their fabrication, structure, mechanism, and properties are highlighted with an emphasis on the electrode material. The remaining challenges and future directions are also summarized to provide useful clues from the viewpoint of practical applications.