Over recent decades mankind has looked afresh to nature to inspire the materials and technological developments which surround us. The advent of microscopy revealed much about the structure of natural materials, and coupled with advances in modelling and chemical and biological synthetic techniques, the methods for understanding the composition and morphology of natural materials has taken significant leaps forward. This chapter introduces the most significant groups of natural materials – the proteins, polysaccharides, biominerals and others – and a selection of their naturally occurring states in biological organisms. The majority of natural materials are in fact composites, utilising two or more components to achieve the properties required by the organism. Therefore the latter part of the chapter looks at composites based on natural fibres, or biopolymers, to introduce the potential of forming biocomposites based on natural materials.