It was the latest blow from a widening clampdown on perceived dissent across the Gulf Arab states.
The verdict in a state security court is certain to bring a fresh outpouring of denunciations by rights groups, which have repeatedly called for the release of poet, Muhammad ibn al-Dheeb al-Ajami. It also marks another example of tough measures by judicial and security officials in the Gulf against possible challenges to their rule since the Arab Spring revolts began last year.
The poet's lawyer, Najib al-Nuaimi, said he planned to appeal.
"This judge made the whole trial secret," said al-Nuaimi. "Muhammad was not allowed to defend himself, and I was not allowed to plead or defend in court. I told the judge that I need to defend my client in front of an open court, and he stopped me."
Al-Ajami was jailed in November 2011, months after an Internet video was posted of him reciting "Tunisian Jasmine," a poem lauding that country's popular uprising, which touched off the Arab Spring rebellions across the Middle East. In the poem, he said, "We are all Tunisia in the face of repressive" authorities and criticized Arab governments that restrict freedoms.
Qatari officials charged al-Ajami with "insulting" the Gulf nation's ruler and "inciting to overthrow the ruling system." The latter charge could have brought a death sentence.
Al-Nuaimi said al-Ajami, a third-year student of literature at Cairo University, has been held in solitary confinement since his arrest.
Gulf regimes have stepped up crackdowns on a range of perceived threats to their rule, including Islamist groups and social media activists. Earlier this month, Kuwait arrested four people on charges of insulting the emir with Twitter posts, and the United Arab Emirates imposed sweeping new Internet regulations that allow arrests for a wide list of offensives, including insulting leaders or calling for demonstrations.
Last year, Bahrain issued a royal pardon for some protest-linked suspects, including a 20-year-old woman sentenced to a year in prison for reciting poetry critical of the government's effort to crush a Shiite-led uprising against the Sunni monarchy.