Interest in polymer optical fiber Bragg gratings (POFBGs) arises from the different material properties and sensing modalities brought by polymers relative to silica. Polymer fibers typically offer twice the sensitivity to temperature of conventional silica fiber and increased sensitivity to strain overall. In addition, polymer fibers have higher elastic limits and as a result a larger range of operation for physical constraints. While some polymers are effectively humidity insensitive, others present inherent humidity sensitivity. Their organic properties also allow a variety of chemical processes to create (bio)chemical sensors, with the consequences of fiber breakage in situ being less hazardous than silica. These attributes have led to the use of POFBGs for applications that remain complex using silica fibers. This review paper covers the progress toward commercialization and the increasing number of specific applications.