The railway line into Ballymena was closed due to a sudden death, police have said.
Emergency services attended the scene between Cullybackey and Ballymena following the incident on Sunday morning.
Translink has said several train services have been delayed.
The train involved was the 9.33am service from Londonderry to Great Victoria Street in Belfast.
A statement by operator Translink said: "We can confirm a man has died on the railway line near Ballymena this morning.
"The line was closed as a result but has now reopened."