In this chapter, we discuss a novel approach, the Physical Internet (PI) that could promote greener transport and circular economies (CE) by promoting innovative resource-efficient logistics systems. The increased use of information and communication technology (ICT) to support logistics solutions will make it much easier to implement environmentally sustainable logistics in the future. Some practical experiments in horizontal cooperation and information sharing in logistics, which greatly support sustainable development, already exist. In addition, several theoretical approaches rooted in the use of advanced ICT solutions have been developed with the aim of creating more sustainable logistics systems. One of these approaches is the Physical Internet Initiative, which has received a lot of interest in the European Union lately. In this chapter, we will describe PI and how it could boost new business models, while enhancing greener transports and CE. The objective of PI is to build an internet for logistics, and to reform manufacturing and logistics networks into a resource-efficient and environmentally sustainable system. In this chapter, we will focus on a discussion on moving physical objects. The chapter starts with an introduction and outline of the literature and history of the concept of PI. It proceeds to describe a layered structure of PI and presents a new model for analysing the PI system, which we envision as an emerging logistical ecosystem spanning multiple industries. We present examples of the emerging business opportunities of PI. Finally, discussion and conclusions are provided.