The flight's 194 passengers all made it off the plane alive, and it landed on Friday at Daegu International Airport with its door still open.
According to local media, some passengers passed out while others had breathing issues and were brought to the hospital.
According to Yonhap news agency, the 30-year-old guy was detained as soon as he landed.
Flight OZ8124, an Airbus A321-200 jet, had taken off from Jeju Island on Friday about 11:45 local time (03:45 GMT).

On social media, a passenger's video of the gap in the plane's left side and the winds buffeting rows of seated people can be seen.
Witnesses told local media that the plane was close to land when the flight attendants could not stop him.
They claimed that after opening the door, the man also attempted to leap out of the aircraft.
Passengers have described the panic on board.
“It was chaos with people close to the door appearing to faint one by one and flight attendants calling out for doctors on board through broadcasting,” one 44-year-old passenger told Yonhap.

“I thought the plane was blowing up. I thought I was going to die like this,” he added.
Several school age children had also been on board, on their way to a weekend sporting event.
The mother of one of the students told Yonhap: “The children were shaking, crying, and frightened.”
Police said the suspect had so far not given any explanation for his actions, nor was he drunk at the point of his arrest.
“It is difficult to have a normal conversation with him,” an official said. “We will investigate the motive of the crime and punish him.”