The University of Duesseldorf's philosophy faculty decided on Tuesday that she had carried out "a deliberate deception through plagiarism".
The minister has denied the claims and said she will appeal.
An earlier plagiarism row brought an end to the political career of Germany's defence minister in 2011.
Large parts of Karl-Theodor zu Guttenberg's 2006 legal dissertations were found by Bayreuth University to have been copied and he stood down before it issued its damning verdict in May 2011.
Using the same words as Duesseldorf's Heinrich Heine University, it concluded that he had "deliberately deceived".
When Ms Schavan became the second minister in Chancellor Angela Merkel's government to be accused of copying her doctorate, in this case by an anonymous blogger, she insisted she had never "knowingly falsely cited any sources" and promised to respond to the accusations.
But the faculty committee concluded that her work, which dealt with the formation of conscience, included a "substantial number of unaccredited direct quotes from other texts".
In a statement declaring the doctorate invalid and withdrawing it from Ms Schavan, the faculty head Bruno Bleckmann said they had "decided by secret ballot, by 12 votes to two, with one abstention".
The minister herself, 57, was said to be on a five-day education and science co-operation trip to South Africa.. Education minister since 2005, she is described as a close colleague of Chancellor Merkel.
Her lawyers reportedly rejected the university's ruling and said Ms Schavan would appeal.
When the university announced its inquiry, she said she had no intention of standing down.
But the investigation into one of Chancellor Merkel's closest allies is seen as potentially awkward months before Germans vote in federal elections.
The popular German newspaper Bild said the news was a bitter blow to the chancellor, and wondered whether she would need to find a new education minister at the start of her election campaign.
- 30/08/2015 17-year-old migrant killed in shootout at sea with Greek police
- 30/08/2015 European ministers agree more railway security, urge Schengen changes
- 30/08/2015 Three refugee children found critically ill in Austria
- 29/08/2015 Turkish planes join anti-IS coalition in Syria raid for first time
- 29/08/2015 Former deputy interior minister of Georgia shot
- 29/08/2015 Turkey: 24 people injured in Mardin bomb attack
- 29/08/2015 Croatia comes out of crisis: PM
- 29/08/2015 Deadly attack in eastern Turkey
- 28/08/2015 PKK have killed 14,000 since 1984
- 28/08/2015 Turkey: PM Davutoglu unveils interim Cabinet
- 28/08/2015 NATO’s support for sovereignty and territorial integrity is strong, says secretary general
- 28/08/2015 2 French journalists held for 'attempted blackmail of Morocco king'
- 28/08/2015 Tusk says EU, Ukraine want to see early free travel
- 27/08/2015 Greece to use EU money to open refugee centres
- 27/08/2015 Dozens found dead in truck on Austrian highway
- 27/08/2015 Opening of NATO training center in Georgia to destabilize region: Russian Foreign Ministry
- 27/08/2015 NATO opens training center in Georgia
- 27/08/2015 Hungary migrant crisis escalates as police fire tear gas
- 27/08/2015 Italy, Spain, US troopers take part in Romania NATO drill
- 27/08/2015 PKK terrorists attack Turkish police; there are wounded
- 27/08/2015 First opposition member joins Turkey's interim Cabinet
- 26/08/2015 Greek president expected to call election on Friday
- 25/08/2015 At least three dead in shootout in northern France
- 25/08/2015 Hollande, Ban Ki-Moon urge efforts for reaching binding accord on Paris climate summit
- 25/08/2015 Merkel to visit protest-hit refugee home
- 25/08/2015 Number of ceasefire violations in Donbas continues to decline — OSCE
- 25/08/2015 Greece says lacks infrastructure to cope with migrant influx
- 25/08/2015 Turkish President Erdogan decides on 'renewal of parliamentary elections'
- 25/08/2015 Flood, landslides 'kill 8 people' in northeastern Turkey
- 24/08/2015 Almost 80,000 sign UK petition for Netanyahu arrest
- 24/08/2015 EU to consider suspending sanctions against Belarus next week
- 23/08/2015 Macedonia reestablishing order at border with Greece as migrants flood
- 23/08/2015 Two prisoners escape from Norway jail shortly after justice minister's visit
- 23/08/2015 Belgium calls on neighbors for more security on cross-border trains
- 23/08/2015 Thousands of migrants rush past police into Macedonia - PHOTO
- 23/08/2015 German minister condemns riots in front of asylum shelter
- 22/08/2015 7 killed in UK airshow plane crash
- 22/08/2015 41 terrorists destroyed as result of operation conducted by Turkish Armed Forces
- 22/08/2015 Clashes as Macedonia becomes latest migrant crisis flashpoint
- 22/08/2015 Three injured in shooting on Amsterdam-Paris train