The verdict concluded that Fillon paid his wife and children, as well as Joulaud, hundreds of thousands of euros from public salaries for little or no work.
Fillon was sentenced to five years in prison, three were suspended, as well as a fine of 375,000 euros ($ 423,000) and a ten-year ban from running in the election.
His wife Penelope was sentenced to a suspended prison sentence of three years and a fine of 375,000 euros.
Filloni and their co-defendant were also ordered to reimburse the French National Assembly more than a million euros ($ 1.13 million).
A scandal breaks out
Fillon was prime minister under President Nicolas Sarkozy between 2007 and 2012.
He then dismissed his claims, saying his wife had worked as his deputy for 15 years and held several roles, including managing the schedule and presenting at cultural events. He also said his daughter and son had been employed in similar jobs for 15 and six months, respectively, which he said was not illegal, but was a “mistake in the verdict”.