The provincial court in León handed down the sentence a week after a judy found him guilty of the murder of the 40 year-old pilgrim whose body was discovered on his land five months after she disappeared while walking the Camino de Santiago.
Denise Pikka Thiem, from Arizona, was last seen on April 5th 2015 in a rural area of northwestern Spain's Leon province while following the French route of the Camino de Santiago, a popular pilgrimage also called the St. James Way.
Five months later, after a renewed appeal for information backed by US Senator John McCain, Spanish police arrested Muñoz and he led them to where he had hidden her body, after chopping off her hands, on his land.
Photo released by the family of Denise Pikka Thiem after she went missing.
Throughout the trial, Muñoz, who had originally given a full confession to police, had refused to answer questions.
"I will not make a statement. I won't answer any questions from prosecutors or my lawyer either," he said.
At the time of his arrest the accused claimed that Thiem appeared on his property "lost and asking for help to find her way back to the pilgrimage route," said his lawyer, Vicente Prieto at the time.
"He claims she asked him to show her the way, then got nervous and somehow, and this has not been made clear, it ended with him hitting her," his lawyer said.
Police said that they believe the perpetrator may have painted fake yellow arrows used to mark the pilgrimage route to divert unsuspecting pilgrims off the official track towards his house.
Prieto told the La Manaña programme that his client had hit his victim with a stick and when she fell to the ground was hit on the head with a stone.
"After determining that she had stopped breathing he then buried her in front of his house," said Prieto.
But Muñoz later dug her up and carried her to a more secluded area of farmland and reburied her. "She was naked, I am not sure why," said the lawyer. "He burned her clothes and her backpack."
Police investigators at the time said they believed the killer may have removed her hands in an attempt to hinder her identification and possible forensic traces of her attacker that may have been under her fingernails after the struggle.
Muñoz in court in León. Photo: AFP
DNA tests confirmed that the remains were those of Thiem and the post mortem report stated that Thiem had received a blow to the head that had most probably caused her death.
Muñoz was also accused of stealing more than €1,000 dollars that Thiem was carrying and that he exchanged for euros at a local bank days after she disappeared.
During the three week trial in which more than 100 witnesses were called, the jury of eight women and one man heard testimony that several other women had been harassed by the accused as they walked the same route.
Muñoz was sentenced to 20 years for murder and three years for violent robbery for the theft of more than 1,000 dollars that Thiem was carrying and that he exchanged for euros at a local bank days after she disappeared.
He was also ordered to pay €120,000 compensation to the victim's parents and a further €30,000 to her brother.