Theodore McCarrick is the highest ranking member of the Catholic Church to be expelled in modern times.
Former U.S. Cardinal Theodore McCarrick has been expelled from the Roman Catholic priesthood after he was found guilty of sex crimes against minors and adults, the Vatican said on Saturday.
Pope Francis has decided that the ruling, which followed an appeal by the man who was a power-broker as Archbishop of Washington, D.C. from 2001 to 2006, was now final.
A Vatican statement said his crimes were made more serious by "the aggravating factor of the abuse of power".
McCarrick, who in July became the first Roman Catholic prelate in nearly 100 years to lose the title of cardinal, has now become the highest profile church figure to be dismissed from the priesthood in modern times.
The decision comes as the Church is still grappling with a decades-long sexual abuse crisis. it has exposed how predator priests were moved from parish to parish instead of being defrocked or turned over to civilian authorities in countries across the globe.
With the ruling, Pope Francis appears to be sending a signal that even those in the highest echelons of the hierarchy will be held accountable.
The ruling, made by the Vatican's Congregation for the Doctrine of the Faith three days ago, was announced ahead of next week's meeting at the Vatican between the heads of national Catholic Churches to discuss the global abuse crisis.
Defrocking means McCarrick can no longer call himself a priest or celebrate the sacraments, although he would be allowed to administer to a person on the verge of death in an emergency.
The allegations against McCarrick, whose fall from grace stunned the U.S. Church, date back to decades ago when he was still rising to the top of the hierarchy there.
McCarrick, who has been living in seclusion in a remote friary in Kansas, has responded publicly to only one of the allegations, saying he has "absolutely no recollection" of an alleged case of sexual abuse of a 16-year-old boy more than 50 years ago.
Vatican spokesman Alessandro Gisotti said the ruling showed that "different treatment for bishops who have committed or covered up abuse in fact represents a form of clericalism that is no longer acceptable."
McCarrick was also found guilty of the separate crime of solicitation, which refers to when a priest uses the pretext of the sacrament of confession to commit an immoral act with a penitent.
One of the men who has claimed that McCarrick abused him when he was a boy said McCarrick, then a priest, touched his genitals during confession.
Separately, several priests and ex-priests have come forward alleging McCarrick used his authority to coerce them to sleep with him when they were adult seminarians studying for the priesthood.
McCarrick has not commented publicly on the allegations of misconduct with adults, which was an open secret in the U.S. Church.