The couple has not met before their wedding day, and will not be able to consummate their marriage until the groom is released in 14 years.
Dilli Koirala, 33, is serving a 20-year sentence for murdering his wife, while 30-year-old Mimkosha Bista has another four years to serve for killing her husband.
The marriage was set up by the groom's mother, who is also in prison for helping her son kill his first wife.
"He murdered his wife and I did in my husband," Bista told Nepalese media after the wedding ceremony.
"His mother likes me and that is one of the reasons I drew close to him," she added.
The couple are both behind bars at Kalikot District Jail, a small prison in rural western Nepal with just 53 prisoners, 50 men and three women.
A lawyer who attended the marriage said the couple decided to tie the knot because they did not think they would find anybody else willing to marry them.
"Since we both happen to have committed the same kind of crime, we won't be in any position to look down upon one another," the groom said, according to local media.
The pair were married by a local priest in a Hindu ceremony witnessed by jail staff and fellow inmates, a prison official said.
The official said the couple would not be allowed to stay together, as there are separate section for men and women prisoners in the jail.
But they will be allowed to meet up twice a month to talk in person.
http://news.sky.com/story/killers-who-murdered-their-partners-get-married-in-nepal-jail-10779686