The Japanese, playing in their first semi-final, beat Sweden by the same score with a double from Nahomi Kawasumi, including a spectacular 35-metre lob, to book a spot in Sunday's final.
On a rainy afternoon, the Americans, who won the title in 1991 and 1999 and have never finished below third place in a Women's World Cup, took an early lead when Lauren Cheney flicked in a Carli Lloyd cross in the ninth minute.
France levelled after the break with a Sonia Bompastor cross that bounced past U.S. keeper Hope Solo but two goals in three minutes from Abby Wambach (79th) and Alex Morgan (82nd) secured a third World Cup final appearance for the Americans.
"This is our journey, this is our dream," a beaming Wambach said. "France are a great team. There were moments they were outplaying us but I am so proud of this team."
"I know we are going to pull through. I have belief in this team. Everybody is working for each other."
In Frankfurt, captain Homare Sawa turned from villain to hero by putting Japan 2-1 up on the hour after her defensive error had given Sweden a 10th minute lead.
Josefine Oqvist pounced on Sawa's disastrous back pass, cut into the box and fired home from a tight angle but Japan recovered quickly as Kawasumi equalised nine minutes later after scrambling the ball over the line.
Sawa added the second with a close-range header after the Japanese had rattled the bar minutes into the second half and Kawasumi completed their comeback in style, catching Swedish keeper Hedvig Lindahl out with a spectacular lob.
FRENCH DOMINANCE
In Moenchengladbach, the Americans, who were under pressure from the start, scored against the run of play through Cheney but immediately dropped deep and some sloppy passing allowed France to come forward repeatedly.
"We lost our legs a bit but we picked up the fight," said U.S. coach Pia Sundhage, whose team needed a penalty shootout to overcome Brazil in the last eight. "I think it was obvious we had heavy legs so we had to adjust."
With Sundhage sensing danger and bellowing from her coaching area, the French dominance almost paid off on the half hour when Gaetane Thiney tested Solo with a close-range effort.
Bompastor then rattled the bar with a fierce drive seconds later as France took complete control.
Wambach, who had scored an equaliser deep into extra-time against Brazil, should have put the Americans further in front before the break but headed along the goal line from a metre.
The French got their just reward after 55 minutes when Bompastor levelled after whipping in a cross from the left that deceived Solo.
With France coach Bruno Bini bringing on another striker in the speedy Elodie Thomis as they went in search of the winner, the Americans struck at just the right time with Wambach making amends and heading in at the far post.
A smooth chip over keeper Berangere Sapowicz from Morgan three minutes later put the game b
