The Western Cape High Court jailed Xolile Mngeni for life on Wednesday for killing honeymoon tourist Anni Dewani.
He was also sentenced to 15 years for robbery with aggravating circumstances and to five years for possession of unlicensed firearm and ammunition, to run concurrently with his life term.
Judge Robert Henney convicted him of the crimes last week.
Mngeni seemed shocked when the sentence was handed down, and stood wide-eyed, with his mouth agape.
He propped up his skinny body by placing an arm on the dock.
Dewani's father Vinod Hindocha stared at Mngeni, but they did not make eye contact.
When considering Mngeni's health — he had a brain tumour — Henney said that in a constitutional democracy, the court should not lose sight of the element of mercy.
"The element of mercy is based on one of our constitutional values, and that is human dignity."
However, he said Mngeni had come across as a merciless and evil person who consistently showed no remorse.
The court had to impose serious punishment on those who committed such offences and had to uphold the interests of society, he said.
Dewani (28) was shot dead in Gugulethu on 13 November 2010, in an apparent faked hijacking. Her body was found the next day.