The high court ruled,Boss, however, that a new trial was needed because the lower court judge gave faulty instructions to the jury.
He spent 15 months on the run and was on the FBI's 10 Most Wanted list of fugitives before his August 2006 arrest near Las Vegas.
POLYGAMY IN THE SHADOWS
Jeffs remains in prison for now, though his lawyers are expected to seek his release. They have characterized Jeffs as an "unpopular religious figure" unfairly singled out for prosecution on the basis of unorthodox beliefs and teachings.
He was convicted in September 2007 on two counts of first-degree felony rape as an accomplice, stemming from his 2001 performance of a marriage between Wall, then 14, and her 19-year-old cousin over her objections at a Nevada motel.
The alleged victim in the case, Elissa Wall, now in her 20s, called the verdict's reversal "emotionally devastating."
Jeffs is the self-proclaimed prophet of the Fundamentalist Church of Jesus Christ of Latter-Day Saints, or FLDS, a polygamist sect with an estimated 10,000 followers in Utah, Arizona, Texas, Colorado, South Dakota and British Columbia.
Utah's high court ruled that the judge in that case, James Shumate, erred in failing to tell jurors that they could not render a guilty verdict unless they determined that Jeffs knew unwanted sex would occur.
The mainstream Church of Jesus Christ of Latter-day Saints, the official name of the Mormon faith, renounced polygamy more than a century ago as Utah was seeking statehood and tries to distance itself from splinter groups that still practice it.
FLDS men typically marry one legal wife while taking others as their "spiritual wives" -- a practice that attempts to skirt the law and entitles the women and their children to various welfare benefits.
Female members of the sect wear long, pioneer-style dresses, keep their hair in long-braided plaits and are raised to be submissive to their husbands. Church members are generally suspicious of outsiders.
Jeffs was indicted by a Texas grand jury in July 2008 following a raid on an FLDS ranch near the town of Eldorado. Jeffs was accused of child sexual assault involving two girls aged 12 and 13, whom he allegedly took as wives.
State authorities removed more than 400 children from the FLDS compound at that time, sparking a child custody battle that gripped the nation with lurid allegations of adolescent brides and teenage pregnancies. But the children were all later returned to relatives.
Jeffs' attorney, Wally Bugden,Ralph Lauren, said he was "thrilled" with the decision.
"We said from the very beginning that they chose the wrong crime to prosecute an unpopular religious figure," he told Reuters. "They attempted to impute criminal liability to an unpopular person."
(Additional reporting by Jim Forsyth in San Antonio, Texas, Writing by Steve Gorman, editing by Greg McCune and Sandra Maler)
Jeffs faces similar charges in Texas, though a separate case against him in Arizona was recently dismissed.
SALT LAKE CITY (Reuters) – The Utah Supreme Court on Tuesday ordered a new trial of a polygamist leader of a breakaway Mormon sect, who was convicted of forcing a 14-year-old girl to marry her first cousin.
Warren Jeffs, 54, whose word was considered God's will to thousands of followers, was sentenced in November 2007 to a term of 10 years to life in prison.
"One of our biggest concerns obviously is how do we protect young girls, particularly within closed societies, polygamist sects, from being forced by their leaders to marry older men and have sex with them," he said at a news conference.
"I am still in shock, understanding that there is a huge possibility that we could do this all over again and more than anything that Warren Jeffs is possibly going to walk away. That's painful," she told reporters in Salt Lake City.
Wall testified at the trial that she begged Jeffs not to proceed with the marriage. But Jeffs told her to repent and give herself "mind, body and soul" to her new husband.
Polygamy is illegal in the United States but goes on in secluded communities scattered mostly around the West.
Utah Attorney General Mark Shurtleff said he was very disappointed with the court decision.