This chapter provides an overview of silicone materials beginning with a brief history of their development, basic nomenclature, and fundamental properties. Siloxane polymer synthesis, various functional groups that can be incorporated into those polymers, methods for preparation, and the nature of crosslinked silicone materials are described. Applications that exploit the unique properties of silicone materials with an emphasis on surface modification and processing considerations for medical-grade silicones are discussed throughout. Finally, efforts aimed at improving the sustainability and recycling of silicones are discussed.