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.
- 21/04/2015 Ahmet Davutoğlu: We commemorate with deep respect Ottoman Armenians who lost their lives and share in grief of their children and grandchildren
- 21/04/2015 800 dead after Sunday's Mediterranean migrant shipwreck
- 21/04/2015 Elmar Mammadyarov: "Considerable progress registered in Azerbaijan-EU bilateral cooperation"
- 21/04/2015 13-year-old student kills teacher with crossbow in Spain
- 21/04/2015 Turkey's top cleric calls Pope 'immoral' for Armenia comments
- 19/04/2015 Slovenian febrile patient cleared of Ebola suspicion
- 19/04/2015 Italy looking forward to removal of Iran sanctions
- 19/04/2015 Russia denies agreement with Greece on gas project
- 19/04/2015 Norwegian journalist arrested in Yemen to come home Sunday: report
- 18/04/2015 Gunmen attack Turkey’s Kurdish party headquarters
- 18/04/2015 Turkish PM: Three-term rule for MPs 'disputable'
- 18/04/2015 Greece seeks more EU aid to cope with soaring immigration
- 17/04/2015 Ahmet Davudoghlu: “Turkey is ready for the best neighborhood relations with Armenia”
- 17/04/2015 Serbian president’s plane to Vatican returns because of engine failure
- 17/04/2015 Turkish PM talks with EU's Schulz over Armenian resolution
- 17/04/2015 İstanbul police capture two would-be DHKP/C attackers in Yenibosna
- 17/04/2015 Greek Police Fear Clash Between Mine Workers and Activists in Athens
- 17/04/2015 Spain: Ex-IMF chief Rato probed by authorities in tax case
- 17/04/2015 European stocks fall on Greek crisis; Wall Street turns higher
- 17/04/2015 Main political parties of Turkey issue a joint declaration condemning the EP resolution
- 16/04/2015 Slovenian suspect of Ebola tested negative
- 16/04/2015 Record number of anti-Muslim acts in France
- 16/04/2015 Forty-one boat migrants reported drowned in Mediterranean: IOM
- 16/04/2015 Former Czech Prime Minister Gross dies at age of 45
- 16/04/2015 Missing Glasgow teen case turns into murder investigation
- 16/04/2015 Germany to sell weapons to Lithuania: officials
- 16/04/2015 Turkey calls EU Parliament’s resolution 'preposterous'
- 16/04/2015 The European Parliament adopts resolution related to the so-called "Armenian genocide"
- 15/04/2015 G7 urges Iran to help resolve Middle East crises
- 15/04/2015 Recep Tayyip Erdogan: "Turkey had no shadow of "genocide" in its past"
- 15/04/2015 Speaker: Turkey determining who will attend Victory Day celebrations in Moscow
- 15/04/2015 Armed incident takes places near Georgian Foreign Ministry
- 15/04/2015 Cemil Cicek: Pope being manipulated as political tool to smear Turkey
- 15/04/2015 Turkey invites Yemen conflict sides to dialogue
- 15/04/2015 Lithuania's new security chief officially starts duty
- 15/04/2015 400 people may have died crossing Mediterranean
- 14/04/2015 G7 summit to discuss Iran nuclear deal, Ukraine
- 14/04/2015 European Parliament to discuss so-called Armenian genocide
- 13/04/2015 Turkey delivers 15 trucks to peshmerga fighting Daesh
- 13/04/2015 Germany dodges Pope's Armenian 'genocide' claims