The sentencing of Liu Xiaobo comes despite international appeals for his release, which China sternly rejected as interference in its internal affairs.
Liu was the co-author of an unusually direct appeal for political liberalization in China called Charter 08. He was detained just before it was released last December. More than 300 people, including some of China's top intellectuals, signed it.
The verdict was issued at the No. 1 Intermediate People's Court in Beijing after a two-hour trial Wednesday where prosecutors accused Liu of "serious" crimes.
"All I can tell you now is 11 years," the defendant's wife, Liu Xia, told The Associated Press. Diplomats said they were told by Liu's lawyers that he had been deprived of his political rights for a further two years.
The vaguely worded charge of inciting to subvert state power is routinely used to jail dissidents. Liu could have been sentenced for up to 15 years in prison under the charge.
Liu is the only person to have been arrested for organizing the Charter 08 appeal, but others who signed it have reported being harassed.
Abolishing the law on inciting to subvert state power is among the reforms advocated in Charter 08. "We should end the practice of viewing words as crimes," the petition says.
The United States and European Union have urged Beijing to free Liu.
"We continue to call on the government of China to release him immediately," Gregory May, first secretary with the U.S. Embassy, told reporters outside the courthouse Friday. May was one of a dozen diplomats stopped by authorities from attending the trial and sentencing.
Foreign Ministry spokeswoman Jiang Yu told reporters this week that statements from embassies calling for Liu's release were "a gross interference of China's internal affairs."
Liu, a former Beijing Normal University professor, spent 20 months in jail for joining the 1989 student-led protests in Tiananmen Square, which ended when the government called in the military - killing hundreds, perhaps thousands.
More than 300 international writers including Salman Rushdie, Umberto Eco and Margaret Atwood have called for Liu's release, saying he should be allowed to express his opinion.
Charter 08 demands a new constitution guaranteeing human rights, the open election of public officials, and freedom of religion and expression. Some 10,000 people have signed it in the past year, though a news blackout and Internet censorship have left most Chinese unaware that it exists.
Liu has been the only person arrested over the charter, but rights groups said several signers have been harassed or fired from their jobs, and warned not to attend the trial or write about it online.