Space architecture is the theory and practice of designing and building habitable environments in outer space. The architectural approach to spacecraft design, based primarily on aerospace engineering, also involves various disciplines including psychology, physiology and sociology, as well as multiple technical areas. As on Earth, space architecture seeks to go beyond components and systems through extensive knowledge of the issues that affect the success of its design. Extensive work has been focused on conceptual designs for orbital stations, exploration ships to the Moon, Mars "Mars (planet)") and surface bases for space agencies, including NASA.

The practice of involving architecture in space programs grew during the space race. It arises from the need to extend the duration of missions and entails the minimum needs of astronauts to live comfortably.

The Sasakawa International Center for Space Architecture SICSA is an organization within the University of Houston that offers a master's degree in space architecture. In Europe, the International Space University conducts extensive research on architecture.