Alex Wiens, 28, stabbed Marwa al-Sherbini, who was wearing a hijab, at least 16 times on July 1, in the same courthouse in the eastern city of Dresden where the trial took place.
The case of Wiens, who has admitted holding anti-Islamic and xenophobic views, shocked Germany and incensed the Muslim world, sparking protests from Egypt to Iran.
Prosecutors said the attack was motivated by "a pronounced hatred of non-Europeans and Muslims".
Elwy Ali Okaz, al-Sherbini's husband, who was stabbed as he tried to protect his wife during the attack, was then shot in the leg by police who apparently took him for the attacker.
Egyptian media quickly dubbed al-Sherbini a martyr and there were huge protests against the murder in several Muslim countries.
Nadim Baba, Al Jazeera's correspondent reporting from Dresden, said the perception of Islamaphobia in Germany was unlikely to go away despite the stiff sentence.
"We've heard calls from people in Egypt for the death penalty, and to be fair to the Egyptian authorities ... they've been at pains to explain to their public that the death penalty doesn't exist in Europe and that what was handed down today was in fact the harshest sentence possible under German law," he said.
"The judges went out of their way to stress that because this was an exceptionally brutal case, after 15 years the killer will be reassessed before there's any chance of him being let out, which is an exceptional measure."
Ramzy Ezzeldin Ramzy, the Egyptian ambassador to Germany, welcomed the verdict, saying:"Justice has been honoured."
"Getting the maximum possible sentence, I think that itself says a lot," he said.
In his closing arguments on Monday, prosecutor Frank Heinrich said there was no doubt of Wiens' reasons.
"It's clear that his motive was hatred for Muslims," Heinrich told the panel of judges.
"Like a maniacal, cold-blooded killer, he started stabbing the woman and her husband, who was trying to protect her."
Al-Sherbini and the defendant met in August 2008, when she asked him to clear a playground swing where he sat smoking a cigarette so Mustafa, her son, could use it.
He refused, calling al-Sherbini an "Islamist", a "terrorist" and a "whore". She pressed charges for defamation and he was fined $1,170.
An appeal against the conviction brought them together again in July.
The defendant allegedly plunged an 18cm kitchen knife into the chest, back and arm of al-Sherbini, 31, three months pregnant at the time with her second child.
Wiens, who arrived in Germany from Perm in the Urals in 2003, reportedly struggled with bouts of depression.
Germany has the second-largest Muslim population in western Europe after France and some groups criticised the German government for taking several days to condemn the murder.Source: Al Jazeera (English)