The Assembly demoparty is a demoscene and gaming event in Finland. It is the biggest demoscene party. The main organizers of the event are Pekka Aakko and Jussi Laakkonen. The Summer event takes place every year between late July and early August, and lasts three to four days, and the Winter event is held in January or February. Edition 2020 was online. The most recent Assembly was held from 3 to 6 of August 2023 at Messukeskus in Helsinki.

The demoscene is an international computer art subculture focused on producing demos: self-contained, sometimes extremely small, computer programs that produce audiovisual presentations. The purpose of a demo is to show off programming, visual art, and musical skills. Demos and other demoscene productions are shared at festivals known as demoparties, voted on by those who attend and released online.