Abstrak - Kajian ini memfokuskan pada diplomasi pertahanan yang dilakukan oleh TNI AL, Badan Keamanan Laut (Bakamla) serta Kementerian dan Lembaga terkait dalam menjaga perbatasan untuk mencegah terjadinya perdagangan orang. Perdagangan orang merupakan salah satu ancaman bagi pertahanan nirmiliter, dimana melibatkan keselamatan segenap bangsa, salah satunya adalah pekerja migran Indonesia. Diplomasi pertahanan untuk aspek tersebut telah dilakukan Malaysia, namun pelaksanaannya belum maksimal karena belum diatur dalam satu payung hukum yang mengkoordinasi seluruh kegiatan kerjasama. Penelitian ini bertujuan untuk menganalisis bagaimana peran diplomasi pertahanan Indo nesia dalam menjaga wilayah perbatasan maritim antara Indonesia dan Malaysia. Selain itu juga menganalisis aspek confidence building measures dan capacity building bagi pihak Indonesia. Analisis juga mencakup aspek koordinasi Kementerian dan Lembaga terkait dalam mencegah terjadinya perdagangan orang yang dialami oleh pekerja migran Indonesia. Metode kualitatif dengan pendekatan studi kasus merupakan desain penelitian yang dilakukan dalam penelitian ini. Metode wawancara terhadap narasumber serta studi literatur digunakan dalam teknik pengumpulan data. Untuk memeriksa keabsahan data digunakan triangulasi antar peneliti dan triangulasi sumber. Hasil penelitian menunjukkan bahwa peran diplomasi pertahanan dalam menjaga wilayah perbatasan maritim antara Indonesia dan Malaysia telah meningkatkan confidence building antara Indonesia dan Malaysia, namun capacity building belum secara maksimal terbangun karena adanya beberapa kendala. Sementara itu, koordinasi Kementerian dan Lembaga sudah ada, namun belum dilakukan secara maksimal karena belum adanya kesepakatan dan payung hukum yang melandasi koordinasi atau kerjasama tersebut. Kajian ini memberi sumbangan bahwa peran diplomasi pertahanan merupakan pendekatan yang penting guna mencegah terjadinya perdagangan orang melalui penjagaan keamanan di perbatasan laut.Kata kunci: Diplomasi Pertahanan, Peran, Perbatasan Maritim, Pekerja Migran Indonesia, Perdagangan Orang                                                                  Abstract - This study focuses on the defense diplomacy carried out by Indonesian Navy, Indonesian Maritime Security Agency (Bakamla) and to the related Ministry and Institutions in guarding borders to prevent human trafficking. Human trafficking is one of the threats to non-military defense, which involves the safety of the nations, for instance, Indonesian migrant workers. Defense diplomacy in this aspect has been carried out by Malaysia, but the implementations has not been maximized yet because it has not been regulated in the legal law which is coordinating all operations activities. The aims of this study is to analyse how the role of defense diplomacy in guarding the maritime border areas between Indonesia and Malaysia. In addition, this study aims to analyse the aspect of confidence building measures and capacity building for Indonesia. The analysis also includes the aspects of coordination of relevant Ministries and Institutions in preventing the occurence of criminal acts of human trafficking experienced by Indonesian migrant workers. This study use qualitative method with case study approach. Interview and literature studies has been used as data collection technique. The inter-researcher and source triangulation has been used to check the validity of the study. The result shows that the role of defense diplomacy in guarding the maritime border between Indonesia and Malaysia had increased the confidence building measures between Indonesia and Malaysia, but the capacity building had not yet been maximally build due to several constraints. Meanwhile, the coordination of Ministries and Institutions already exists, but has not been carried out optimally because there is no agreement and legal law that underlies about the coordination or cooperation. This study contributes that the role of defense diplomacy is an important approach to prevent human trafficking through security at maritime borders.Keywords: Defense Diplomacy, Role, Maritime Borders, Indonesian Migrant Workers, Human Trafficking