Former PricewaterhouseCoopers employees Antoine Deltour and Raphael Halet received 12 and nine-month sentences respectively for leaking documents.
Prosecutors had sought 18-month jail terms for the two men.
Edouard Perrin, a journalist who reported on the leaks, was acquitted of all charges.
Deltour, 31, and Halet, 40, also received suspended fines of €1,500 (£1,250; $1,650) and €1,000 euros respectively.
They have 40 days to appeal the verdict. Deltour told Agence France-Presse that he intended to appeal.