Beate Zschaepe, 43, was found guilty of 10 counts of murder in deadly shootings of nine Turkish and Greek-born immigrants as well as of a German policewoman. The murders were carried out by a trio known as the National Socialist Underground (NSU).
Although life imprisonment in Germany typically means 15 years behind bars because prisoners are often released for good conduct, Zschaepe would not be eligible for parole as judge Manfred Goetzl imposed the maximum sentence due to the "exceptional severity of the crime."
Foreign Minister Heiko Maas vowed to combat such neo-Nazi hate by upholding Germany's commitment to tolerance and rejecting extremism.
"We not only stand up to racist violence with the strength of the law. Intolerance and hate must be met with the diversity of our open societies," he wrote on Twitter, adding that "the victims remain unforgotten."
Police say the other two members of the NSU - Zschaepe's former lovers Uwe Mundlos and Uwe Boehnhardt - carried out their killing spree from 2000 to 2007, before they died in an apparent suicide pact following a bungled bank heist in 2011.
Mundlos "hated the multicultural melting pot in Germany," said Goetzl, noting that he also developed an anti-Semitic video game, in which players shot Jews.
"The accused Zschaepe took on the far-right views of her environment," said the judge, adding that she formed a firm bond with racist friends.
The Munich court case that opened in May 2013 ended after hearing some 800 witnesses and experts, with 93 bereaved relatives as co-plaintiffs.
It was Germany's biggest trial since the 1960s Auschwitz hearings against perpetrators of the Holocaust, and the 1970s proceedings against the left-wing extremist Baader-Meinhof gang.
But victims' relatives say many questions remain unanswered.