IDEF (International Defence Industry Fair) is one of the leading and globally recognized fairs in defence industry. Hosted by Türkiye, this international fair brings together defence industry companies, military officials, experts, and other stakeholders in the defence sector to showcase innovative technologies and explore cooperation opportunities.

IDEF is organized under the management and responsibility of Turkish Armed Forces Foundation and is held biennially. Beginning in 1993, the fair has provided a significant platform for introducing the latest developments, products, and technologies in the defence industry. At the Fair, a wide range of products and services are exhibited, including naval, air, and land systems, military equipment, security devices, weapons, ammunition, and defence electronics. Participants include defence industry companies, military officials, defence industry experts, government representatives, media organizations, academics, and non-governmental organizations.

17th International Defence Industry Fair, IDEF 2025, will be held at Istanbul Expo Center from July 22 to 27, 2025. The Fair is hosted by Turkish Ministry of National Defence, supported by Presidency of the Republic of Türkiye Secretariat of Defence Industries, managed by Turkish Armed Forces Foundation, and organized by KFA Fairs Organization Inc.