The flight had to be diverted to Cork after the man became unwell.
A 24-year-old man, believed to be a foreign national, became unwell an hour into the two hour journey from Lisbon to Dublin.
He became agitated and bit another passenger, he then fell unconscious and died shortly afterwards.
A medical emergency was declared and The Aer Lingus flight EI485 had to be diverted to Cork Airport, where it landed at around 5:40pm.
The 170 passengers and crew members were taken from the plane, interviewed by Gardaí and transferred by bus to Dublin Airport.
