The British No 1 controlled the match from the outset, breaking Roddick at the first opportunity in both sets on his way to a 6-3, 6-1 victory in just 59 minutes.
Roddick could simply not touch him as Murray, who has put all concerns over his ankle injury behind him, produced an exhibition of top-class tennis.
Murray mixed his game up magnificently, passing Roddick with some exquisite winners and teasing the American with some traditional drop-shots.
"I got off to a good start. Andy is one of the toughest guys to break on the tour. I managed to get a break early in both sets, everything that touched my racket was going in," said Murray. "That doesn't happen much on court. I was lucky."
Murray came racing out of the blocks, moving into a 3-0 lead before going 4-1 up with two perfect drop shots. Murray took Roddick to deuce before the American held for a 4-2 lead but he had no way back into the set.
The world number four fired down two aces to claim a 5-2 lead and then fizzed three more past a stunned Roddick to wrap up the opening set.
There was no let-up from Murray in the second set as he fired two forehand winners past Roddick to claim a pair of break points. He needed only one as Roddick netted a volley.
Murray held for 3-1 and then moved a second break up with another deft drop shot before unleashing a forehand winner on the run. It was a masterclass.
Murray was pouncing on Roddick's usually deadly serve and he despatched a backhand and then a forehand winner before breaking for a third time to seal a stunning victory.
The Scot will face Jo-Wilfried Tsonga in the final. The Frenchman defeated surprise package James Ward 6-3, 7-6 (9-7) in the second semi-final.
* Press Association