Samsung's Jay Y. Lee was arrested in the graft scandal.
A panel of three judges also found Lee guilty of embezzling Samsung funds, hiding assets overseas, concealing profit from criminal acts and perjury. Other former top executives who advised Lee were also sent to prison or given suspended terms.
Samsung, a symbol of the country's rise from poverty following the 1950-53 Korean War, has come to epitomise the cosy and sometimes corrupt ties between politicians and the chaebols.
Considered one of the world's largest smartphone and memory chip makers, the full outcome of the verdict is yet to be fully seen.
Lee is said to have offered bribes to Park Geun Hye when she was the President of the country.
The elder Choi first became close with Park following the death of her mother at the hands of a North Korean assassin in 1974, while Park's father, dictator Park Chung-hee, was president.
The South Korean won strengthened to near four-week highs on Monday as the US dollar slumped after the Jackson Hole conference where global central bankers failed to say quite what markets wanted to hear. "The essence of the case is unethical collusion between political power and capital", the court said in a statement.
Out of 43.3 billion won - the total amount of the money which the special counsel viewed as paid or promised by Samsung Group - the court acknowledged only 8.92 billion won as a bribe.
No More Plastic Bags for Kenya
Plastic bags, El-Habr said, take 500 to 1,000 years to break down and can enter the human food chain if fish or other livestock ingest the items.
The ruling for Samsung Group's de facto chief is not yet final. Lee's succession over Samsung. It is set to report its highest-ever earnings this year. "But the conglomerate will face hurdles in making long-term decisions for finding future growth engine and strategies".
But they have more recently been criticized for holding back the economy and stifling small businesses and start-ups. Samsung accounts for about one fifth of the nation's exports.
It marks the downfall for the scion of South Korea's richest family, which controls one of the world's largest consumer electronics companies.
As of June this year, the owner's family members including the vice chairman and friendly shareholders have 19.86% of Samsung Electronics.
Numerous key witnesses and her former subordinates have already turned their backs on the ex-president during court proceedings, saying that they had committed alleged wrongdoings under Park's order.
Samsung has not denied transferring funds. But Lee, vice chairman at Samsung Electronics and the Samsung founder's grandson, claimed innocence during the court hearing. He said he was unaware of the foundations or the donations, which were overseen by other executives.
The sentencing is the latest episode in a scandal that saw millions of South Koreans protest last autumn, leading Park to be ousted. The trials are now being carried out separately, but given that these charges are two sides of the same coin, the judges assigned to the Park case can't help but take this judgement into consideration.
"Lee's imprisonment shows they are down to business quite seriously this time". The attempts to hide Samsung's involvement also constituted crimes, it said. Lee has two sisters, but neither has been heavily involved in Samsung Electronics, which is widely regarded as the center of the Samsung empire.