The 22-year-made his England debut in the pre-tournament friendly against Mexico after receiving his first international call-up, but the Manchester City winger was not among the 23 players named in the final squad.
Tottenham defender Michael Dawson says he is "gutted" to have missed out on a place in England's 23-man squad for the World Cup finals.
Dawson told talentnation.com: "I was gutted at not being involved, but I'll certainly be watching all the games and cheering the lads on.
"The boys in South Africa are going to rock. We are going to win it [the World Cup]."
Dawson's manager Harry Redknapp, meanwhile, accused Fabio Capello of treating England's fringe players, including Dawson and West Ham's Scott Parker, like "ghosts".
Redknapp told The Sun: "People on the inside who I know tell me Scott was fantastic in training every day. He worked his socks off and could not have done any more, but whatever he did he wasn't going to go.
"Someone said to me he felt like a ghost on the trip, like Dawson - they were there but not there, and they could sense that. They never kicked a ball and the manager didn't really speak to them or give them much feedback.
"Capello might as well have taken 25 to Austria instead of 30. They made up the numbers."
Adam Johnson has vowed to take the positives out of his World Cup disappointment, and says he has been reassured about his international future by England's management.
"Of course I was a bit down when I got the news and my first thought was that I wish I'd had more of a chance to show what I could do in the two warm-up matches," he told mcfc.co.uk.
"I would have loved the chance to showcase what I can do on the biggest stage of all but I am not going to dwell on it. The England management made it clear to me that I have an international future and I am going to have a rest now and then get my head down and get ready to try and work my way into the side for September qualifiers.
"I suppose if you had mentioned the World Cup to me back in December I would have smiled but I had a thought in the back of my mind when I signed for City that if I did well I might have half a chance. I am going to take the positives out of the last two weeks."
Johnson came into the England reckoning after joining City from Middlesbrough in January, and then dislodging Shaun Wright-Phillips – who is in the World Cup squad - from Roberto Mancini's starting XI.
Johnson's versatility appeared to count in his favour, but he played only six minutes of the friendly against Mexico before remaining on the sidelines throughout the Japan clash.
"I have worked with the squad, I have an England cap which is a wonderful honour and I know that I will be in the mind of the coach and his staff for the future," Johnson added.
"I am an England fan and in a way I built up so many bonds in the last couple of weeks that I will still feel part of it. I have spoken to Shaun, wished him good luck and told him to go and do well. There are certainly no hard feelings towards him.
"I am delighted for Gareth [Barry] too. He has had a great season and it would have been so cruel for injury to have robbed him of a World Cup.
"The lads are fully capable of winning the World Cup. I think we have a great chance along with maybe two or three other sides. Of course we will need a bit of luck along the way that goes with winning anything in sport but no one should write off England's chances."
Theo Walcott was still in a "state of shock" tonight after the Arsenal winger, once described by Fabio Capello as the nation's "best talent" and the man who ignited the side's qualification campaign, was left out of the England squad for the World Cup.
A surprise inclusion four years ago, the midfielder became this summer's unanticipated omission after a season wrecked by injury was compounded by subdued displays in the recent friendly victories over Mexico and Japan. Capello has instead opted to pick Shaun Wright-Phillips, who lost out to Walcott for a place in the 2006 finals.
It is understood Walcott had no inkling that his position was in any doubt. He was on the golf course today and initially disbelieving when Capello telephoned to relay the news.
Gareth Barry has been included after proving his fitness in tests this morning – he should be available for the second group game, against Algeria, on 18 June – while Everton's Leighton Baines was omitted in favour of Stephen Warnock, who has six minutes of international football to date but will serve as Ashley Cole's back-up.
The others to miss out on tomorrow's flight to Johannesburg from the provisional 30-man squad were Darren Bent, Scott Parker, Tom Huddlestone, Adam Johnson and the uncapped Michael Dawson.
Yet it was Walcott's exclusion that drew the focus. The Arsenal winger, the man who had kickstarted England's qualification campaign with a stunning hat-trick in the 4-1 win over Croatia in Zagreb in the autumn on 2008, had been sitting the theory section of his driving test four years ago before his father delivered a more positive message from Sven-Goran Eriksson – but was left devastated this time around once realisation that he had been dropped had sunk in.
"I am very disappointed not to be included in the squad going out to South Africa, but completely respect Mr Capello's decision," Walcott said. "I would like to wish the team the best of luck and hope they have a really successful tournament."
He told the club’s official website: "I feel really disappointed. I've always said to myself - if you play well and do your best for Sunderland then there's a chance you can go to the biggest tournament in the world. But obviously on this occasion it hasn't worked out."
"Straight away from when Mr Capello spoke to me and told me I wouldn't be involved in the 23-man squad, my thoughts turned to next season and how I can improve on what I've done for Sunderland this past year.
"I'm going to take some time off now and rest my bones after what's been a great season for me and get ready for next year. It's just a case of fully concentrating on my football for Sunderland and doing my best for them.
"Of course I still want the boys to do well. I've got a lot of friends in the England set up. They're a great bunch of lads and even though I won't be there, I'll be supporting them."
Despite scoring 24 Premier League goals last season, Bent was not expected to be named in Fabio Capello’s World Cup squad after the Italian had favoured Wayne Rooney, Peter Crouch, Jermain Defoe and Emile Heskey throughout qualifying.
And, for no-one in particular other than myself, premier league represent in the England 23:
Chelsea: the two Coles, JT, Don Lampard
Tottenham: Crouchie, Jermain Defoe, Aaron Lennon, Ledley King
Liverpool: Steven Gerrard, Jamie Carragher, Glen Johnson
Man Utd: Michael Carrick, Rio Ferdinand, Wayne Rooney
Man City: Gareth Barry, Joe Hart, SWP
Aston Villa: Stephen Warnock, James Milner, Emile Heskey
West Ham: Rob Green, Matthew Upson
Portsmouth: David James