Olmert's lawyers said they would likely appeal the ruling by the Jerusalem District Court. He'll be sentenced at a later court hearing.
Olmert was acquitted in 2012 of a series of charges that included accepting cash-stuffed envelopes from US businessman Morris Talansky when Olmert was mayor of Jerusalem and a Cabinet minister before he became prime minister.
The verdict was seen as a major victory for Olmert.
But Olmert's former office manager and confidant Shula Zaken later became a state's witness, offering tape recordings of conversations with Olmert about receiving cash, leading to a retrial.