Ward Churchill, who had vowed to sue if the Board of Regents took action against him, said immediately after the 8-1 vote was announced: "New game, new game."
Three faculty committees had accused Churchill of plagiarism, falsification and other misconduct. The research allegations stem from some of Churchill's other writings, although the investigation began after the controversy over his Sept. 11 essay.
"The decision was really pretty basic," said university President Hank Brown, adding that the school had little choice but to fire Churchill to protect the integrity of the university's research.
"The individual did not express regret, did not apologize, did not indicate a willingness to refrain from this type of falsification in the future," Brown said.
Churchill's essay mentioning Sept. 11 victims and Nazi leader Adolf Eichmann prompted a chorus of demands for his firing, but university officials concluded it was protected speech under the First Amendment.
Brown had recommended in May that the regents fire Churchill after faculty committees accused him of misconduct in some of his academic writing. The allegations included misrepresenting the effects of federal laws on American Indians, fabricating evidence that the Army deliberately spread smallpox to Mandan Indians in 1837, and claiming the work of a Canadian environmental group as his own.
But the essay that thrust Churchill into the national spotlight, titled "Some People Push Back: On the Justice of Roosting Chickens," was not part of the investigation.
That essay and a follow-up book argued that the Sept. 11, 2001, terrorist attacks were a response to a long history of U.S. abuses. Churchill said those killed in the World Trade Center collapse were "a technocratic corps at the very heart of America's global financial empire" and called them "little Eichmanns."
Churchill has said Eichmann was a bureaucrat who carried out policies like the Holocaust that were planned by others but was still responsible for his own actions.
Churchill wrote the piece shortly after the attacks, but it drew little notice until 2005, when a professor at Hamilton College in upstate New York called attention to it when Churchill was invited to speak there.
In the uproar that followed, the regents apologized to "all Americans" for the essay, and the Colorado Legislature labeled Churchill's remarks "evil and inflammatory."
Bill Owens, then governor of Colorado, said Churchill should be fired, and George Pataki, then governor of New York, called Churchill a "bigoted terrorist supporter."
School officials concluded Churchill couldn't be dismissed because he was exercising his First Amendment rights. But they launched the investigation into his research in other work.
A faculty committee and an interim chancellor recommended Churchill be fired. When a second committee reviewed the case, three of its five members recommended a suspension. The other two said he should be fired.
Churchill remained on the university payroll but had been out of the classroom since spring 2006, first because he was on leave and later because the school relieved him of teaching duties after the interim chancellor recommended he be fired.
The lone no vote on Tuesday came from Regent Cindy Carlisle, who was not immediately available for comment.