Thomas Cook Group plc was a global travel group, headquartered in the United Kingdom and listed on the London Stock Exchange from its formation on 19 June 2007 by the merger of Thomas Cook AG — successor to Thomas Cook & Son — and MyTravel Group until 23 September 2019, when it went into compulsory liquidation. The group operated as a tour operator and airline, and also operated travel agencies in Europe. At the time of the group's collapse, approximately 21,000 worldwide employees were left without jobs and 600,000 customers were left abroad, triggering the UK's largest peacetime repatriation.

Thomas Cook AG was an Anglo-German, global travel group. The group had its headquarters in Rochdale, and sold products such as package holidays and flights through its 3 in-house airlines. On 19 June 2007, the group merged with MyTravel Group plc to form the Thomas Cook Group plc, which was listed on the London Stock Exchange.