Material selection is inherently linked to the economic, social and environmental value of a product-packaging system. While the properties of a packaging material and the process by which it is converted into a packaging component contribute to its effectiveness, strategies to optimise environmental performance are informed by an understanding of material life cycles. Paper and board products, polymers, glass, aluminium and steel are the most widely used packaging materials, although there is increasing use of renewable materials such as starch and cellulose. This chapter provides an overview of the life cycle and applications of commonly used and emerging packaging materials.