Bae, 44, was born in South Korea but is a naturalised American citizen and attended the University of Oregon. According to U.S. media, he most recently lived in the Seattle suburb of Lynnwood.
A North Korean defector said Bae will likely serve his sentence in a special facility for foreigners, not in one of the repressive state's forced labour camps. More than 200,000 people are incarcerated in these camps, beaten and starved, sometimes to death, according to human rights bodies.
Bae's sentencing comes after two months of sabre-rattling by Pyongyang that saw North Korea threaten both the United States and South Korea with nuclear war.
Bae is believed to be a devout Christian, according to human rights activists in South Korea, who say he may have been arrested for taking pictures of starving children, known as "kotjebi" or fluttering swallows.
He was part of a group of five tourists who visited the northeastern North Korean city of Rajin in November and has been held since then.
Some media reports have identified Bae as the leader of the tour group and NK News, a specialist North Korea news website, said he was the owner of a company called Nation Tours that specialised in tours of north-east North Korea.
The reports could not be verified and North Korean state news agency KCNA did not list any specific charge other than crimes against the state, and used a Korean rendering of Bae's name, Pae Jun-ho, when it reported the Supreme Court ruling.
"North Korea has shown their intention to use him as a negotiating card as they have done in the past," said Cheong Seong-chang, senior fellow at the Sejong Institute, a Seoul-based think-tank.
Bae's sentence was heftier than the 12 years handed down to two U.S. journalists, Laura Ling and Euna Lee, in 2009. It took a visit to Pyongyang by former President Bill Clinton to secure their release.
North Korea appears to use the release of high profile American prisoners to extract a form of personal tribute, rather than for economic or diplomatic gain, often portraying visiting dignitaries as paying homage.
According to North Korean law, the punishment for hostile acts against the state is between five and 10 years hard labour.
"I think his sentencing was hefty. North Korea seemed to consider his acts more severe," said Jang Myung-bong, honorary professor at Kookmin University in Seoul and a North Korea law expert.
North Korea is one of the most isolated states on earth. Its official policy of "Juche" or self-reliance is a fusion of Marxism, extreme nationalism and self sufficiency centred on the cult of the ruling Kim family.