3D Printing represents one of the emerging technologies in the age of digitization and intelligence. It has been drawing the attention of scientists in many fields, including civil engineering. The relevant research work in the field of civil engineering has been in progress since the 1990s and has made great progress during the past decade. Development of 3D printing concrete and concrete structures is challenging, because it involves interdisciplinary research, e.g., material science, structural engineering, mechanical engineering, automatic control engineering, information technology, software engineering, mechanics, physics, chemistry, mathematics, environmental engineering, etc. The main focuses of current research are on the material of printable concrete, the equipment for printing concrete, printed components and structures, and applications to large-scale structures. This technology exhibits promises in structural optimization, elaborate constructions reducing redundancy, and intelligent construction under extreme conditions. This Special Issue is planned to provide an overview of the frontiers of the development of 3D printing concrete and concrete structures. It is aimed to identify the knowledge barriers across disciplines, remove the barriers, and to promote the application of 3D printing technology in civil engineering.