John Richard Whiteley (28 December 1943 – 26 June 2005) was an English presenter and journalist, best known for his 23 years as host of the game show Countdown. Countdown was the launch programme for Channel 4 at 4:45 pm on 2 November 1982, and Whiteley was the first person to be seen on the channel (not counting a programme montage). Whiteley enjoyed projecting the image of an absent-minded eccentric. His trademarks were his jolly, avuncular manner, his fondness for puns, and his bold, sometimes garish wardrobe.

Thanks to over 20 years' worth of daily instalments of Countdown as well as his work on the Yorkshire magazine programme Calendar and various other television projects, at the time of his death Whiteley was believed to have clocked more hours on British television screens—and more than 10,000 appearances—than anyone else alive, apart from Carole Hersee, the young girl who appeared on the BBC's Test Card F.

Whiteley was born on 28 December 1943 in Bradford, West Riding of Yorkshire, the first child of Thomas (1912–1992) and Margaret (née Bentley) Whiteley (1918–2001); he had a younger sister, Helen, who died in March 1998 aged 49 of cancer. Whiteley spent his childhood in Baildon: his family owned a long-established textile mill, Thomas Whiteley and Co of Eccleshill, which went out of business in the 1960s. At 13, he won a scholarship to Giggleswick School, Yorkshire, where his English teacher was Russell Harty. He later became a governor of the school. From 1962, he read English at Christ's College, Cambridge.

On leaving Cambridge in July 1965, Whiteley served three years as a trainee at ITN but left to join the newly created Yorkshire Television in July 1968.

In 1973, Whiteley and Woodrow Wyatt presented the Anglia Television documentary The Red Under the Bed, about the trial of the Shrewsbury Two (Des Warren and Ricky Tomlinson) which was broadcast on the day that the trial jury retired to consider their verdict. The programme, which was heavily critical of the trade union movement, is now considered to have swayed jurors into returning a guilty verdict and was later cited by the Criminal Cases Review Commission as evidence that the verdicts were unsound. Warren and Tomlinson's convictions were overturned in 2021. Speaking in 2017 about the documentary, Tomlinson claimed to be in possession of confidential documents proving that it had been funded and written by British intelligence services and that Whiteley had been employed by MI5 at the time of broadcast.

Whiteley was bitten by a ferret on an edition of Calendar in 1977. The animal bit his finger for half a minute before its owner, Brian Plummer, prised it free. The clip is often repeated on programmes showing television outtakes and Whiteley once joked that when he died, the headlines would read, "Ferret man dies". He said, "It's made a lot of people laugh and it's been shown all over the world. It's 30-odd years since it happened and I think I've been a great PR man for the ferret industry. Ferrets have a lot to be grateful for; to me, you see, they've become acceptable because one of them bit me."

In 1982, Yorkshire Television began to produce Countdown, copying a French quiz show format, Des chiffres et des lettres. Whiteley was chosen as host and continued with the show when Jeremy Isaacs brought it to Channel 4 as the first programme broadcast by the new station. Its first broadcast received over 3.5 million viewers, but the programme lost 3 million viewers for its second show.^{[citation needed]}

However, it gradually rebuilt its audience over the following weeks. It was as the host of Countdown that Whiteley became known to a wider audience in the United Kingdom outside the Yorkshire region. He was nicknamed "Twice Nightly Whiteley", in reference to the time when he would present the Calendar news programme and Countdown in the same evening, from 1982 to 1995. (In a self-deprecating joke, he often countered this with "Once Yearly, Nearly".)