In a rematch of last year's final, Swiatek recorded another straight-sets victory over the American player as she chases her third trophy at the clay-court major.
Gauff fell to 0-7 against Swiatek, and the Floridian has yet to take a set against her. Swiatek, a 22-year-old Polish player, won 6-1, 6-3 in last year's final.
In the semifinals, Swiatek will face Beatriz Haddad Maia, who scored another comeback win in upsetting Ons Jabeur 3-6, 7-6 (5), 6-1 to become the first Brazilian woman since 1968 to reach a Grand Slam semifinal.
Swiatek claimed the match's first break but allowed Gauff to hit back and level the first set at 3-3 by crashing a volley into the net. Swiatek got back on track with a superb crosscourt winner that she celebrated by pumping her fist and letting out a big scream.
"It was not easy," said Swiatek, the first player since Conchita Martinez in 1995 to drop 15 or fewer games en route to the semifinals in Paris. "Especially the first set. It was tight and Coco was using the conditions well, so I was happy that I was able to win. The quarterfinals are sometimes the toughest matches.
"Today was a tighter match. I'll be ready for the next one."
In the second set, Swiatek took a tumble at the net after nearly being struck by a Gauff rocket before producing a tight hold for a 2-1 lead and grabbing another break with a perfectly placed lob.
She settled the contest by pouncing on Gauff's serve again and finished the victory when the 19-year-old found the net.
The Associated Press and Reuters contributed to this report.