The 69-year-old Peronist was sentenced by a panel of three judges.
Fernández de Kirchner, who was Argentina's president between 2007 and 2015, is accused of accepting billions in bribes in the procurement of publicly funded projects.
She herself denies the accusations.
Because Fernández de Kirchner is vice president, she enjoys immunity and cannot be jailed.
The ruling cannot become final until the appeals – which are expected – have been dealt with, which could take years.
In a first comment after the verdict, Cristina Fernández de Kirchner announced that she does not intend to run for any political post in the 2023 general election.
"I will not run for anything, not for senator or for the nation's vice president," she writes on social media.
Before the verdict, Cristina Fernández de Kirchner's supporters had threatened to "paralyze the country" if she was convicted.
Ahead of the verdict, large crowds demonstrated in central parts of the capital Buenos Aires and marched towards the federal court building.
Many beat drums and tried to force the police barriers.