This paper explores several lamellar structures found in nature, which have been shown to possess superior armor systems. In particular, the hard armor systems of nacre and conch shells, and the flexible armor system of fish scales are the focus of this review due to their high relevance to the protective structural engineering discipline. The structure–function relationships that govern the superior mechanical performance of these systems are attributed to their well-organized composite hierarchical structures. The paper also reviews advancements in additive manufacturing techniques for proof-of-concept prototyping, as well as advanced modeling techniques that have been employed to capture the complex geometries of biological structures and the interactions between their constituents. Finite element modeling and 3D printing were found to be the most popular techniques, as they automate the process of modeling and manufacturing complex bio-mimetic composites from a computer-aided design. Finally, attempts to apply bio-mimicry to the structural engineering discipline have been identified, which remains a new and exciting area of research.