The 2006 transatlantic aircraft plot was a terrorist plot to detonate liquid explosives, carried on board airliners travelling from the United Kingdom to the United States and Canada, disguised as soft drinks. The plot was discovered by British police during an extensive surveillance operation. As a result of the plot, unprecedented security measures were initially put in place at airports. The measures were gradually relaxed in the following weeks, but passengers are still not allowed to carry liquid containers larger than 100 ml onto commercial aircraft in their hand luggage in the UK and most other countries, as of 2022.

Of 24 suspects who were arrested in and around London on the night of 9 August 2006, eight were initially tried for terrorism offences in connection with the plot. The first trial took place from April to September 2008. The jury failed to reach a verdict on charges of conspiracy to kill by blowing up aircraft but did find three men guilty of conspiracy to murder and acquitted one other of all charges. In September 2009, a second trial (of the now seven originally accused but with the addition of another man) found three men guilty of conspiracy to kill by blowing up aircraft and one other guilty of conspiracy to murder, while the 'additional' man was cleared of all terrorism charges.In July 2010, a further three of the accused were found guilty at a third trial at Woolwich Crown Court of conspiracy to murder. Thus, of the nine men tried, two were acquitted and seven found guilty of conspiracy charges.