Khodorkovsky's co-defendant Platon Lebedev was also found guilty of the same charges and was given the same sentence.
Khodorkovsky and Lebedev were also ordered by the court on Tuesday to pay more than US$615 million in taxes and penalties.
Khodorkovsky's lawyers are expected to appeal the guilty verdict and sentence in the 10-day period allotted under Russian law.
The prosecutor-general's office, meanwhile, reiterated that new criminal charges against Khodorkovsky were being prepared.
Tuesday's ruling came on the 12th day of the laborious verdict-reading process in the most closely watched trial of post-Soviet Russia, and one that has been widely criticised as politically motivated.
Khodorkovsky's trial was most
watched in post-Soviet Russia
Khodorkovsky, the former head of the Yukos oil company and once estimated to be Russia's richest man, has already spent 583 days in jail, meaning he will serve about another seven and a half years in prison.
Supporters have claimed that Khodokovsky's trial was part of a Kremlin-driven campaign to punish him for funding opposition parties and to stifle his own political ambitions.
The sentence would keep him in prison past the 2008 presidential elections and potentially during the 2012 elections as well.
Khodorkovsky, whose fortune was once estimated as high as $15 billion, has been in jail since his October 2003
arrest when special forces stormed his private plane on the tarmac of a Siberian airport.
The verdict "shows that in Russia there is no independent court, in Russia there is only the all-powerful prosecutor-general", liberal politician Irina Khakamada said.
"In Russia there is no independent court, in Russia there is only
Demonstrators' chants of "Shame, shame!" could be heard even inside the courtroom as the proceedings continued after the sentencing.
"This verdict is a tragic example of the authorities turning a legal system against an individual for political ends," Yukos spokesman Alexander Shadrin said.
Yukos announced shortly after the verdict and sentencing of Khodorkovsky that it had filed a court challenge to the production unit's sale and would seek 324 billion roubles ($11.6 billion) in damages.