A significant change is occurring in the global polymer industries. Development of a new generation of bio-based polymers, polymers derived from renewable resources, is progressing rapidly. Complementing historical biopolymers such as natural rubber and cellulosics, these new bioplastics include a growing number of commercial successes, including polylactides and polyhydroxyalkanoates. Many more bioplastics are on the near horizon, made possible by rapid advances in biotechnology. The molecular specificity of biochemical transformations is ideally suited for producing high purity monomers needed for making high molecular weight polymer molecules. Some of the newest developments involve the creation of well-established polymers (polyethylene, polybutlylene, poly(ethylene terephthalate)) via new biochemical pathways that start with renewable, rather than fossil, resources. This article highlights some recent advances in bio-based polymers. Specifically, this review includes topics ranging from novel biopolymer synthesis, new bio-based nanocomposites, novel processing, and holistic assessments of sustainability through quantitative life-cycle analysis. It is demonstrated that greener plastic materials can be produced through ecologically responsible conversion of renewable resources using industrial biotechnology and enhanced by nanotechnology. This emerging approach represents a triple technological convergence that promises to significantly alter the value chains of the global plastics industries.