The BBC television series Dragons' Den first aired in the United Kingdom in 2005.
The programme debuted on BBC Two as a British adaptation of the international Dragons' Den format. Entrepreneurs enter before a panel of wealthy investors and present their businesses, usually seeking money in exchange for an ownership stake. The central format has remained recognisable since the first series: a pitch, questioning, negotiation and a decision from the investors.
The British version followed the Japanese business programme Money Tigers, which began in 2001. Dragons' Den became one of the BBC's best-known factual entertainment shows and later inspired versions in many other countries. Its title uses “dragons” for the investors, while the American version is better known as Shark Tank.
The launch year is sometimes confused with the dates of later changes, such as the programme's move to BBC One or the arrival of new investors. Those developments happened after the original BBC Two debut, so 2005 is the key date for the British series itself.