University student Elin Ersson booked what she thought was the same flight as the Afghan, refusing to sit down unless he was taken off the plane.
The migrant in question was not on the flight after all, but another Afghan was onboard for deportation after serving a prison sentence.
Since the protest in July 2018, both Afghans have been expelled from Sweden.
Ersson, 21, broadcasted her protest on Facebook from the Turkish Airlines plane, which was bound for Istanbul, Turkey, from Gothenburg, Sweden.
In the video, Ersson said she did not agree with Sweden's policy of sending back rejected asylum seekers.
"I'm not going to sit down until this person is off the plane, because he will most likely get killed," she said.
The video shows how airline crew and other passengers urge her to sit down and to stop filming.
Ersson was eventually removed from the plane, along with a 52-year-old Afghan and his escort from the Swedish Prison and Probation Service.
Social media reactions were largely supportive of her action, although some people are accusing her of grandstanding.