<p>Nanoarchitectonics has emerged as a pivotal paradigm for the design and development of functional nanoparticles, enabling the precise integration of atoms, molecules, and nanoscale structures to create materials with novel properties and multifunctionality. This review highlights key advances in nanoparticle synthesis, structural control, and applications in catalysis, energy, environmental remediation, sensing, and biomedicine. Notable progress includes the creation of multifunctional core–shell particles, stimuli-responsive carriers, and high-performance biosensors, demonstrating enhanced performance and sustainability. By focusing on representative breakthroughs, we elucidate how nanoarchitectonics addresses challenges in energy efficiency, environmental safety, and advanced healthcare. The unique design philosophy of nanoarchitectonics underpins its role in achieving targeted delivery, high biocompatibility, and improved sensor capabilities, paving the way for next-generation materials and industrial applications. These recent developments illustrate the indispensable role of nanoarchitectonics in driving innovation for a sustainable and technologically advanced society.</p>