Natural silk exhibits extraordinary properties and is useful for various applications. However, silk is produced in limited quantities and is also not easy to be dissolved, modified, or manipulated for specific applications. With a goal to find an alternative to natural silk, attempts have been made to dissolve proteins and regenerate the proteins into fibers using various approaches. Regenerated protein fibers generally called “azlons” were commercially produced from the proteins in corn, soybean, peanuts, and milk and also poultry feathers during the early 1930s. The poor quality of the protein fibers produced, the use of toxic chemicals during fiber production, and the introduction of inexpensive regenerated cellulose and synthetic fibers led to the decline and eventual elimination of the azlons. Although currently there is very limited or no commercial-scale production of regenerated protein fibers, recent advances in biotechnology, increase in the availability of low-cost biofuel coproducts that contain proteins, environmental awareness on using nondegradable fibers, and distinct properties of protein fibers have renewed interests in regenerated protein fibers. Reproducing proteins through biotechnology, developing novel methods to dissolve proteins and improving the properties of fibers, and biomimicking are some of the approaches that are being considered to develop regenerated protein fibers. This chapter provides an overview of such approaches, properties of the fibers developed, and potential applications of the fibers.