Chiles' contract with the BBC runs until the end of April, and the presenter is expected to take some time out before returning to lead ITV's World Cup coverage in June.
The surprise move from the anchor of the BBC's popular 'The One Show' will reunite Chiles with the programme's creator Peter Fincham, now director of television, channels and online at ITV.
Fincham is believed to have played a major role in tempting Chiles away from the BBC after 15 years service.
At ITV, Chiles will front a range of high profile programming, including ITV's football coverage and, later in the year, take the lead role on weekday breakfast show 'GMTV'.
World Cup activity will include England's two peaktime opening games, and from next season Chile's will be in the chair for the Champions League, England's home internationals and away friendlies as well as The FA Cup – the best portfolio of live free-to-air games in the country.
Chiles will also host a new factual entertainment series from 2011.
Fincham said he was "very much looking forward" to working with Chiles again, calling him a "brilliant presenter, journalist and a football fanatic".
He said: "He has the rare talent of being able to make television presenting look effortless. He will be at home at ITV whether it is on our flagship breakfast programme or in the football studio."
For his part, Chiles said he was "absolutely delighted to be part of his [Fincham's] ambitious plans for ITV."
In a surprisingly bitter statement, Chiles also admitted ITV's offer came during "an awkward period" at the BBC, during which time it was announced he would be dropped from his Friday slot on The One Show in favour of Chris Evans.
In an unguarded attack on BBC controller Jay Hunt, the 43-year-old presenter said: "I would have been happy to stay at the BBC doing the same shows on the same terms, especially 'The One Show', of which I am so proud having worked on it since the first pilots four years ago.
"It's no secret how disappointed I was by the controller's decision to change an apparently successful and well-loved show at this stage, but fully respect her right to do so and sincerely wish her and the brilliant 'One Show' team well with it."
The BBC had planned for Chiles to take a key role in its Olympic 2012 coverage in addition to his ongoing presenting duties on 'The One Show', 'Match of The Day 2' and 'The Apprentice: You're Fired'.
A BBC spokesman said: "We would like to thank Adrian for all his contributions over the years and wish him well for the future."