Peter Francis Colbert, 57, was earlier found guilty of the manslaughter of Robert Brimson because he failed to repair brakes he knew to be problematic before a fatal crash.
Mr Brimson died in 2014 when his truck slammed into a pole in suburban Happy Valley, the 45-year-old veering away from other motorists as he desperately pumped his failed air brakes.
In the South Australian Supreme Court on Tuesday, Colbert was sentenced for his conduct in the landmark negligence case.
The widow of the victim, Agnes Brimson, earlier said in her victim impact statement that her life would never be the same again without her husband.
"They were looking forward to travelling together in their retirement and now that will never be realised," Justice Malcolm Blue said in sentencing Colbert.
He was the sole director and shareholder of his trucking company and was responsible for the upkeep of a fleet of 11 trucks, including the 14-tonne vehicle with the faulty brakes.
The boss had known about the brake problems as he had been told several times by other drivers but he still made his employees get behind the wheel, the court heard.
"It (driving the truck) involved such a high risk that death or serious injury were possible," Justice Blue said.
The case is believed to be the first time in SA that a company owner has been found culpable for an employee's death because of negligence.
Colbert was also sentenced for recklessly endangering the life of another driver, Shane Bonham, who experienced a near miss in the same truck only days before the fatal crash.
Mr Bonham was diagnosed with post-traumatic stress disorder and depression after the ordeal and couldn't work for 11 months.
"He still has nightmarish visions of the truck stuck against the pole," Justice Blue said.
The judge said he had not seen evidence of real remorse from Colbert, who, based on a psychologist's report, met the criteria of "narcissistic personality disorder".
Colbert was jailed for 10 years and six months with a non-parole period of seven years and five months.
He was previously found guilty of the same offences but had the verdicts overturned on appeal and a new trial ordered.