A series of international conferences and symposia focused on deep mixing alternated between Japan (1996, 2002, 2009) and Sweden (1999, 2005). 2015 marked the first event in the series to be held in North America (San Francisco, Calif.). Important advances in materials, equipment, system design, and project delivery mechanisms have occurred since 2015. Deep Mixing 2020 will provide a forum for international exchange of this new information. The conference will be structured around plenary sessions and concurrent breakout sessions to optimize benefits to all participants. In keeping with the focus of this series, the conference scope consists of deep mixing and mass mixing by mechanical means that may be assisted by fluid energy. Leaders in the international deep mixing community are pleased to present this seventh conference in a series on deep mixing. For almost 25 years, this consortium of global practitioners has organized and presented these events to advance the understanding, use and performance of deep mixing internationally. The archives from these international conferences contains a wealth of knowledge that charts the evolution of the understanding of material properties, new technologies, research, mix designs, and quality control and assurance for wet and dry deep mixing methods.