He joins Steve Davis, Stephen Hendry and Mark Williams in winning both the UK Championship and the world title and clinching the number one spot in the rankings in the same season.
The victory is fine reward for O'Sullivan, who has been in scintillating form over the past two weeks.
He fired a superb 147 in his second-round win over Mark Williams and had 12 century breaks, with five of the highest 10, during a memorable tournament.
And in his semi-final against seven-time Crucible champion Stephen Hendry, O'Sullivan produced what the Scot called "snooker perfection" as he claimed a stunning 17-6 victory.
O'Sullivan wants to win more world titles
In the final, O'Sullivan only showed glimpses of the form that defeated Hendry but was never really tested by a player competing in his first ranking event final.
"I'm just happy to have won, it was tough," said O'Sullivan. "When you get ahead you are always thinking at the back of your mind, if you lose it from here it is going to be a killer.
"Sometimes it is better when it is closer, sometimes when trying to protect a lead it is hard. If you are playing well you can cruise on but I was struggling.
"I did the damage in one session in every match. I wasn't playing fantastic every session, but you don't need to be to win this. Sometimes you just have to do it in spells.
"Ali and I are disappointed not to put on a better performance but when you get to the final sometimes the balls go scrappy and when you have 1,000 people breathing down your neck it is a tough place to think straight.
"But we love the pressure and excitement at The Crucible."
O'Sullivan, who this week faces a disciplinary hearing after his comments at the recent China Open, also said that he might take a break from the game in order to recharge his batteries.
O'Sullivan tops the prize-money list for the fifth straight season
"Hopefully it is not the last title, hopefully there are a few more to come," he added. "I said I would like to win more, but it is quite well documented that I struggle with the game and with myself.
"Sometimes I think it would be good to go out on a high. I will have a think over the summer and it might be a good time to take a break. Who knows?"
Carter looked jaded after a gruelling fortnight which saw him edge past Joe Perry in a marathon semi-final.
Against O'Sullivan, the 28-year-old from Tiptree was undone by a failure to make the most of a number of opportunities that came his way as his opponent struggled to hit top gear.
But he will satisfy himself with a runners-up cheque of £125,000, plus a half share of the £157,000 awarded for claiming a maximum break during the quarter-final against Peter Ebdon.
"I am pleased to get to the final, it has been a great experience," he said. "I am disappointed not to perform at my best but it is very tiring.
"Ronnie made it very difficult. His safety was brilliant and the better man won on the day.
"The top eight in the world, a maximum and the final of the World Championship - I would have taken that at the start."
Carter was pleased to have gained experience of the Crucible final
O'Sullivan had a six-frame advantage overnight and he went into the final two sessions odds-on favourite to complete the job - no-one has ever recovered from such a heavy overnight deficit in snooker's most prestigious tournament.
He extended his lead with runs of 52, 71 and 69 although Carter made sure the match went into the final session with breaks of 84 and 71.
The start of an evening session was delayed after a streaker entered the auditorium and spread-eagled himself under the match table.
But the interruption did not put O'Sullivan off his stride and a break of 69 in frame 25 left Carter needing snookers, taking him to the verge of victory.
And in the next O'Sullivan sealed the win after being let in when Carter missed a blue into the middle pocket.
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