Wire arc additive manufacturing (WAAM) is an emerging technology for metal processing that offers many advantages for aerospace-grade production. It provides significant design complexity and freedom offering very fast material deposition rates and relatively good material properties. It is also based on simple hardware and materials and is easy to apply in the field, making it an ideal tool for the aerospace industry. This article reviewed the major application sectors in the aerospace industry where WAAM has been successfully used with some examples, some of the aerospace-relevant modeling and simulation work for WAAM that has been done, and the current status of the significantly used WAAM materials of interest to the aerospace industry (particularly, aluminum, titanium, and nickel alloys). It was found that the most important benefits offered by WAAM to the aerospace industry were its very fast material deposition rate, its flexibility and simplicity, and its ability to process aluminum alloys much more effectively than most other AM processes. There are still areas to be explored before WAAM could be fully integrated into the aerospace design and manufacturing system, but it is well on its way and promises to be an essential technology in the future.