非军事区（英语：de-militarized zone，DMZ），亦可译为非武装区、非军事化区等。原为军事术语，一般是指在接近停战线（armistice demarcation line）间，对有领土纠纷所设立的缓冲区。在现代，也被用于信息安全用语中。

设置非军事区的目的，多以降低或避免冲突再爆发为主。在非军事区内的交战双方，所属的各军事力量或装备，除非另有约定，都应撤出非军事区。

世界上的非军事区多被视为中立领土，即交战双方均主张对其拥有主权、非殖民地、非无主地、非租借地等。

非军事区往往会形成两个国家间的事实边界，少部分非军事区也形成了自然保护区。

A demilitarized zone, DMZ or DZ is an area in which treaties or agreements between nations, military powers or contending groups forbid military installations, activities or personnel. A DMZ often lies along an established frontier or boundary between two or more military powers or alliances. A DMZ may sometimes form a de facto international border—for example, the 38th parallel between North and South Korea. Other examples of demilitarized zones are a 120-mile (190 km) area between Iraq and Kuwait, Antarctica (preserved for scientific exploration and study) and outer space (space more than 100 miles (160 km) from the earth's surface).