Cho was jailed for a year in February but the court on Friday ruled she should serve a suspended sentence.
She was convicted of violating plane safety after ordering a taxiing plane back to the gate to offload a steward who had served the nuts the wrong way.
But the appeal court ruled she did not cause a change in the flight path.
It gave Cho a reduced sentence of 10 months and suspended the prison term for two years.
She remains guilty of using violence against flight attendants.
The BBC's Steve Evans in Seoul said Cho looked pale and visibly thinner when she left the court, after changing out of her green prison overalls.
She did not answer questions from reporters and quickly left in a car.
Cho, also known as Cho Hyun-ah, was a vice-president of Korean Air. She is also the daughter of the company's chairman.
On 5 December last year, Cho became angry while onboard a Korean Air flight in New York after she was served macadamia nuts which she did not ask for, and which were still in a bag, not in a bowl.
She confronted both the flight attendant who served her and chief steward Park Chang-jin about the presentation, at one point jabbing Mr Park with a service manual.
Cho then ordered the plane, which was taxiing at JFK Airport, to return to the terminal to offload Mr Park.
Cho had been in custody since she was arrested on 30 December. In February she was convicted and sentenced to one year in jail.
One of the judges on the appeal panel said on Friday that they had taken into consideration that she was a first time offender. "It appears that she will have to live under heavy criticism from society, and stigma," he said.
The case attracted intense attention in South Korea, reopening a national debate about the Korean business system, which is dominated by family firms known as chaebols.
Some of the families running these businesses have been accused of high-handedness and acting with impunity.
Source: BBC News
