United Airlines flight 840 departed from Sydney, Australia but returned to the airport after colliding with the bird shortly after takeoff, a United spokesman said.
No passengers or crew were injured but emergency crews attended the scene.
"We were only in the flight maybe 30 minutes," passenger Anne Hankins told the Associated Press. "[The] pilot came on and said that people in the front had seen birds, and that the pilot had seen birds, a flock of birds flew into both engines, and so they were going to turn us around and come back but it would take about 45 minutes."
She described the plane circling over the ocean burning fuel before flying back to Sydney. "People I mean were obviously nervous but very, very calm on the flight," Hankins told the AP. "They prepared everybody and said this is just a precaution and the plane landed smoothly."
The plane was temporarily taken out of service for maintenance, though the extent of the damage was not immediately known, a United Airlines spokesman said.
Passengers will be re-booked on a flight leaving Sydney on Tuesday, according to the company.