The 2006 transatlantic aircraft plot was an alleged terrorist plot to detonate liquid explosives carried on board several airliners travelling from the United Kingdom to the United States and Canada. The plot was discovered by UK police before it could be carried out, and as a result unprecedented security measures were immediately put in place. This sudden imposition caused chaos and delayed flights for days.

The restrictions were gradually relaxed in the following weeks, but the ability of passengers to carry liquids onto commercial aircraft is still limited.

Of the approximately 24 suspects who were arrested in and around London on the night of 9 August 2006, eleven were charged with terrorism offenses on 21 August, two on 25 August (subsequently discharged on 1 November), and a further three on 30 August.

The trial began in April 2008, and the prosecution began with the exhibition of suicide videos and the allegation that the suspects had bought chemicals.