Polymer nanocomposites (nanoscale filler particles embedded within a macromolecule matrix) constitute attractive platforms to precisely modulate a material’s chemical and physical properties, as the disparate characteristics of these two components can be combined to achieve properties not exhibited by either component alone. While such composites potentially offer a massive design space to tailor material performance, in practice there are severe restrictions that arise from uncontrolled or unfavorable interactions between the filler and matrix. Moreover, many desirable properties depend on the 3D organization of constituent materials as much as their relative compositions, requiring that the composite structures be hierarchically organized across the atomic, molecular, nano-, micro-, and macroscopic scales. Addressing these challenges in materials chemistry requires new molecular, macromolecular, and nanoparticle building blocks to address fundamental questions on materials design, synthesis, and processing. Important targets would include high inorganic content composites, the formation of specific nano- or meso-scale ordering within a composite, and tailored microstructural features; each of these would permit new applications for composites in biomedical, energy, structural, and transportation-related technologies. In this seminar, I will highlight our recent work exploring pathways to designing nanocomposites via the integration of supramolecular chemistry, polymer synthesis, and materials processing. Our group has established a suite of “brush particles” that are inherently composite architectures containing rigid inorganic particle cores, soft polymer brush coatings, and supramolecular binding groups that dictate interactions between the polymer and nanoparticle components. I will outline the advancements that guide our thinking about composite synthesis, underscore key design motifs for brush particle-based nanocomposites, and detail how materials chemistry and processing permit the formation of materials with controlled hierarchical organization across 7 orders of magnitude in length scale simultaneously.