The objective of this paper is to provide an overview of ultralightweight composite mirror technology. The overview includes a description of the technology, differences between traditional and composite designs, significant industry-wide, demonstrations of the technology based on available literature 1-18, and a projection for future applications. The emergence of composite designs provides exciting potential for nontraditional, accurate, lightweight, stable, stiff, and high strength composite mirrors, such as those shown in Figure 1. This evolving technology promises significant improvement in reducing weight, cost and cycle time for future infrared, visible, and x-ray systems. Customers currently embracing composite mirror technology for radiometric use are already reaping substantial system performance benefits. Other customers interested in lidar, IR, visible, and grazing incidence x-ray applications are eagerly awaiting successful completion of current technology development and demonstration efforts.