The verdict concluded that Fillon paid his wife and children, and Joulaud, hundreds of thousands of euros of public salary for little or no work.
Fillon was sentenced to five years in prison, three of them suspended, as well as a fine of 375,000 euros ($ 423,000) and a ten-year ban for running for election.
His wife, Penelope, was sentenced to three years in prison and a fine of 375,000 euros.
Fillons and their defendant colleagues were also ordered to return more than one million euros ($ 1.13 million) to the French National Assembly.
Fillon was prime minister under President Nicolas Sarkozy between 2007 and 2012.
He rejected claims at the time, saying his wife worked for 15 years as his representative and handled several roles, including arranging his schedule and representing him at cultural events. He also said his daughter and son were employed in the same position for 15 months and six months respectively, which he said was not illegal, but constituted “an error of judgment.”