Defence and Security Equipment International (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. The edition of this year is ongoing from 9 to 12 September.

It is a pivotal event for the global defence industry. As the flagship defence event for the UK, Dsei UK promotes the UK’s defence ethos, agenda and leadership while encouraging opportunity and cooperation with global allies.

The world’s leading defence organisations and most influential stakeholders rely on Dsei UK's unique ability to bring the right people together, at the same time. 

Its global reach attracts participants from around the world, offering access to international governments, ministries of defence, and military officials, alongside all UK Front Line Commands.

Some numbers of the edition in 2025. 

1,600+ Exhibitors

90+Countries Represented

45,000+Unique Attendees.