In recent years, protein-based nanoparticles or bionanoparticles (BNPs), have been used as primary building blocks to generate ornate nanomaterials for a wide-range of applications. Over the past fifty years, numerous BNPs have been chemically modified or genetically engineered to function as smart drug/gene delivery vehicles, advanced vaccine vehicles, and isolated reaction vessels for inorganic, metallic, and semi-conductive depositions. These studies have contributed invaluable insights to the expansive capabilities of these simple, yet highly robust, nanosized building materials. Here we highlight some of the recent progress in the chemical modifications of BNPs and hopefully inspire the development of many new materials in the near future.