Electronic devices are evolving from rigid devices into flexible and stretchable structures, enabling a seamless integration of electronics into our everyday lives. The integration of a variety of electronic materials within thermal-drawn fibers has emerged as a versatile platform for the fabrication of advanced functional fiber electronics. This approach exploits the thermal drawing of a macroscopic preform, where functional materials or prefabricated devices are arranged at a prescribed position, yielding kilometers of electronic fibers with a sophisticated architecture and complex functionalities in a very simple and scalable manner. A single strand of fiber that incorporates materials with disparate electronic, optoelectronics, thermomechanical, rheological and acoustic properties can see objects, hear sound, sense stimuli, communicate, store and convert energy, modulate temperature, monitor health and dissect brains. Integrating these electronic fibers into fabrics, ancient yet largely underdeveloped forms, is setting a stage for fabrics to be the next frontier in computation and Artificial Intelligence. Here, we critically review the development of thermally drawn fiber electronics and highlight their unique opportunities in communications, sensing, energy, artificial muscles, 3-D printing, healthcare, neuroscience as well as in-fiber materials fundamental research. We conclude some perspectives for realizing an analogue of “Moore’s law” in fibers and fabrics and the remaining challenges for future research.