Defence and Security Equipment International (DSEI, formerly stylized DSEi) is a biennial defence and security trade exhibition which serves as a forum between governments, national armed forces, industry, and academics, held at ExCeL London.
DSEI 2019 comprised c. 1700 exhibitors from 58 countries,[1] and DSEI 2023 is scheduled for 12–15 September 2023.[2][needs update]