Stretchable and conductive fibers are building blocks for the development of a wide range of wearable and stretchable electronics owing to their small size, light weight, omnidirectional pliability and elasticity, and outstanding integration ability. Despite a large number of reports in the past decade, there is a lack of a continuous and scalable approach to manufacturing stretchable and conductive fibers with sufficient strength, elasticity, conductivity, and durability. Here we report a high-throughput fabrication method based on continuous multimaterial thermal drawing and chemical deposition processes to produce highly stretchable and conductive fibers, which are suitable for being twisted into textile yarns, woven and knitted into textile fabrics, or braided and stitched onto textile structures. We demonstrate the assembly of these stretchable and conductive fibers into breathable, machine-washable, and wearable devices for body motion detection, electrothermal therapy, and electrocardiograph signal detection.