Nature provides the prime examples of lightweight, stiff, strong, and yet tough materials. Their unique properties are realized via the hierarchical self-organization of hard (inorganic, protein crystals, crystalline polysaccharides) and soft (organic, biopolymeric) building blocks. Nacre, wood or silk are the paradigms in materials design and teach the importance to achieve highly ordered and defined structures over several length scales. Among them, nacre (or mother of pearl) exhibits a notable combination of stiffness (40-70 GPa), strength (80-135 MPa), and toughness (3000 times higher than aragonite monolith) originating from the complex hierarchical arrangement of reinforcing CaCO3 platelets (95 vol%) nicely aligned within the energy-dissipating biopolymer matrix in an alternating hard and soft manner. These unique mechanical properties of nacre along with its defined structure inspire researchers for nacre-mimetic nanocomposites. In this contribution, I will discuss how structurally ordered layered nacre-mimetic nanocomposites are prepared via water-borne self-assembly process using polymer as soft binder and 2D nanoplatelets as hard building blocks. The optimization of mechanical properties (in terms of stiffness, strength, and toughness) of these highly reinforced nanocomposites by controlling the composition and feed ratio will be discussed. Furthermore, I will show how nanoplatelet dimensions (aspect ratios), thickness of the organic layers, supramolecular bonds in the soft phase and humidity influence local dynamics and macroscopic material and fracture properties. In terms of functionality, several features like shape-persistent fire-blocking and self-extinguishing properties, glass-like transparency, high gas barrier, printability, and aniosotropic conductivity which are exhibited by the nacre-mimetic nanocomposites will be discussed.