The American finished joint-fourth in the season-ending race alongside Austrian rival Nicole Schmidhofer, while Liechtenstein’s Tina Weirather failed to finish.
'She's done it again!' - Shiffrin clinches Super-G Crystal Globe
Neureuther says goodbye with final run in Soldeu
Germany’s Viktoria Rebensburg won the race ahead of Austria’s Tamara Tippler and Italy’s Federica Brignone.
"I dreamed about someday maybe being able to win a globe in super-G but I wasn't really expecting it this season," said Shiffrin.
'I was never really expecting something like this!' - Shiffrin stunned by Super-G Globe
"The way I've been skiing super-G all season, I didn't know if it would be enough to win. I knew I would have to be aggressive and it worked out just enough."
Shiffrin is almost certain to win a fourth crystal globe in the Giant Slalom on Sunday. Petra Vlhova of Slovakia must overturn a 97-point deficit in the final race, with only 100 points available for a win.
The 24-year-old has already wrapped up the overall and Slalom title, taking her tally in each competition to three and six respectively. She becomes the first woman since Tina Maze in 2013 to win titles in a technical and speed event in the same season.
Additional reporting via Sportsbeat
See how Clement Noel claimed slalom crown in Soldeu
Shiffrin: I wanted to really, really earn it