About 13,000 people arrived, Le Figaro newspaper reported before the beginning of the speech, citing the organizers, while Fillon himself later addressed the crowd of 15,000.
Both the candidate and his wife Penelope, who is currently investigated by the French prosecutors, reportedly received standing ovations.
Penelope Fillon is accused of having been paid fraudulently while working as her husband's parliamentary assistant.
"In front of 15,000 witnesses I want to tell Penelope that I love her and that I will never forgive those who wanted to throw us to the wolves," Fillon was quoted as saying.
On Thursday, Fillon said he would drop out of the presidential race if an inquiry into him was open. On Saturday, French media alleged that The Republicans' candidate himself had misappropriated the funds allocated fr his assistants.
The first round of the presidential elections is scheduled for April 23, while the run-off is slated for May 7. According to the polls, Fillon's main competitors are the National Front leader Marine Le Pen and an independent candidate from the left Emmanuel Macron.
