TEHRAN, Young Journalists Club (YJC) - Fillon, who served as prime minister under President Nicolas Sarkozy from 2007 to 2012, was at one point the front-runner in France's 2017 presidential race.
But he saw his bid unravel over allegations he paid his wife Penelope and two of their children more than 1 million euros ($1.1 million) from 1981 to 2013 for jobs as parliamentary aides that involved no sustained work.
The judicial official confirmed a report in Le Monde newspaper that the couple will stand trial.
The official spoke on condition of anonymity because they are not authorized to discuss the case publicly.
According to Le Monde, Marc Joulaud, who replaced Fillon as a lawmaker in the National Assembly while Fillon served as prime minister, will also stand trial for misuse of public funds.
Fillon has denied wrongdoing, contending the allegations were a smear campaign to undo his presidential bid.
He was handed preliminary charges in March 2017, including for misuse of public funds and improper declaration of assets.
His wife was also charged that year with misuse of public funds, receiving money from a misuse of company assets and receiving money from a fraud.
Fillon kept on running for president despite the corruption investigation, which he denounced as "political assassination."
From the start of 2017, when the investigation began, Fillon had to limit his campaign events to rallies and a few visits under high security to avoid anti-corruption protesters shouting "Fillon in prison!"
The 2017 election was won by Emmanuel Macron, a young upstart centrist.
Fillon had served five times as a government official under two previous presidents, Francois Mitterrand and Jacques Chirac.
In 1981, Fillon was elected to parliament for the first time, representing Sable-sur-Sarthe, a small town in rural western France.
At 27, he was the youngest lawmaker in the lower house of parliament, the National Assembly.