The Rocket took the three frames he needed from an overnight score of 14-10 to reach his fifth World Championship final.
The defending champion will be hot favourite to secure his fifth title against either Barry Hawkins or Ricky Walden who are both fighting to reach their first final.
Yesterday, O'Sullivan courted controversy when he was admonished by referee Michaela Tabb for an obscene gesture he made with his cue.
He was also overheard to say: "I want to go home" during the match.
Today was strictly business though as he looked in firm control throughout.
Trump hit back with a break of 77 from when he was 16-10 down to prolong the contest but the frame before proved to be crucial as Trump left a free ball to his opponent when fouling on the pink while trying to play a safety shot back to baulk.
It came after an opening frame in which Trump was presented with a chance to clinch it but he failed and O'Sullivan punished him.
Curiously, O'Sullivan won the match without scoring a single century - and Trump only scored one - but always looked the more likely to win frames in one visit.
His safety play was also consistently good as he ran out a deserved victor.
Any fears that the Rocket is falling out of love with the Crucible already again seemed to be quashed when he fist-pumped to the crowd at the end of the contest to show just how much the triumph meant to him.
The four-time world champion will now await Walden or Hawkins in the knowledge that neither of his opponents has played in a world final and he has never lost one.