The chief engineer received 30 years and 13 other crew members were sentenced to up to 20 years in prison, Yonhap news agency and other South Korean media reported, citing Gwangju District Court in southern South Korea.
Three other key crew members were earlier indicted by prosecutors on homicide and other charges. Eleven others faced less serious charges.
The 15 crew members tasked with navigating the ‘Sewol’ have faced scathing public criticism because they escaped the sinking ship while many of their passengers were still trapped inside.
A total of 476 people were aboard the ship and only 172 were rescued.
Most of the dead were teenage students travelling to a resort island on a school trip.
Nearly seven months after the sinking, 295 bodies have been recovered but nine are still missing.