Research advances on speech technologies and Natural Language Processing have contributed to their incorporation into a large number of applications and research fields, many of them with a growing interest in the military domain. Clear examples of this are automatic speech recognition and synthesis, automatic translation, virtual training environments, emotional state detection, automatic speaker recognition, detection of topics, automatic language identification, evaluation techniques, standards development, etc. This chapter is focused on the description of the value of these technologies for military applications, covering different systems that have been developed for improving military health care, screening mental status in military situations, developing fighting simulations and videogames, establishing ecologically-valid virtual environments, training military staff to communicate with civilians in foreign countries, or managing critical situations. In addition, the chapter provides a detailed survey on the main technologies behind such applications, with a special emphasis on natural language communication and speech interaction.