Food packaging today relies heavily on plastics such as PP (polypropylene) and PE (polyethylene), from which short-lived, cost-effective packaging materials are made. Their accumulation in the environment has becomes a significant concern. PHB (Polyhydroxy butyrate) is a naturally produced polyester, which can be used as biodegradable thermoplastics. PHB has similar properties to PP and is seen as sustainable replacement candidate for this fossil commodity polymer. PHB is biodegradable, also in the marine environment. Key benefits of PHB over PP are lower carbon footprint and avoidance of “white pollution”, which manifests itself e.g. as marine debris and microplastics. Bioplastics today have a market share of only 2%, and it is materials that can replace mass products such as PE and PP which can really pave the way for more sustainable plastics. PHB will play a key role here. In this review article, the state-of-the-art in PHB production and applications is discussed. PHB can be produced from sugar, but also from CO2 using cyanobacteria. Applications include packaging in general and food packaging in, a major field for short-lived plastics products where biodegradability is a strong benefit.