This paper presents a bibliometric review of 303 studies on Industry 4.0 (I4.0) in the defense sector obtained from the Web of Science (WoS) platform, published in 227 academic circles, authored by 1211 academics. The objective was to broadly and comprehensively identify the concept of I4.0 within the defense sector and identify future research paths. The documents were analyzed using the Bibliometrix tool in the R software. Based on citation analysis metrics, we revealed the most influential articles, journals, authors and institutions. Using the bibliographic coupling methodology, we identified four research clusters: (1) additive manufacturing, 3d printing, spare parts, (2) internet of things, deep learning, military, (3) machine learning, suicide, prediction and (4) Systems, Artificial Intelligence, Expert System.The clusters were analyzed in detail and then a research agenda was proposed.