Iarnród Éireann has said all train services in and out of Heuston Station in Dublin have resumed after disruption earlier this morning.
The company apologised for the inconvenience.
A section of the line between Sallins and Newbridge had been closed at the request of gardaí, who are investigating a fatality.
Commuter services were operating between Sallins and Heuston only, with no commuter services between Portlaoise, Portarlington, Monastervin, Kildare and Newbridge to Heuston.
Intercity services from Cork, Kerry, Limerick, Galway, Westport and Waterford were also affected.