The question before the tournament was whether anyone could stop Swiatek becoming only the third woman to win three French Open titles in a row.
She is aiming to join Monica Seles (1990–1992) and Justine Henin (2005–2007) as the only women to achieve the feat in the Open era.
Only former world number Naomi Osaka, who had little previous form on clay and won her four majors on hard courts, has come close to stopping her.
Swiatek has gone up several gears since that titanic second-round contest – where she saved a match point before winning in three sets.
She did not drop a game in a 40-minute thrashing against Anastasia Potapova in the fourth round and made light work of 2019 finalist Marketa Vondrousova in the quarter-finals.
Paolini is the final player in Swiatek’s way after reaching a maiden major singles final with a powerful performance against Andreeva.
The late-blooming Italian’s run at Roland Garros is the latest surprise in a season where she has registered several career milestones.
Paolini had never previously gone beyond the second round in Paris, but has built on lifting the first WTA 1,000 title of her career in Dubai and earning notable wins over some established top-20 players.
After beating third seed Elena Rybakina in the quarter-finals, she continued to use her powerful forehand to draw mistakes from 38th-ranked Andreeva.
The teenager, who was the youngest Grand Slam semi-finalist since Martina Hingis at the 1997 US Open, was visibly emotional as the second set ran away from her.
“I learned a bit later than other players maybe but to dream is the most important thing in sport and life. I’m happy I could dream this moment,” Paolini, who won the final five games of the match, said.