Commuter (Iarnród Éireann) - Commuter Services - C

• Northern: This route operates from Dublin to Dundalk, with its central terminus at Dublin Connolly. The route is shared as far as Malahide with the DART service. The trains run on the Dublin-Belfast line.
• South Eastern: This route operates from Dublin to Gorey, with its terminus at Connolly Station, and is shared with the DART as far as Greystones. This route is shared with trains to Rosslare.
• Western: This route has two branches in the city centre, one starts at Docklands railway station, while the other starts from Dublin Pearse. The two converge at Broombridge, with the line going as far as Longford. In September 2010, services on this line were introduced from the Docklands to M3 Parkway.
• South Western: This route operates from Dublin to Portlaoise, with its central terminus at Dublin Heuston. In November 2016, services from Newbridge to Grand Canal Dock, which operate through the Phoenix Park Tunnel, were introduced on this line.

• Cork Kent-Mallow Line - Stations at Kilbarry, Monard and elsewhere had been proposed for the future.
• Cork Kent-Cobh Line - Calling at Little Island, Glounthaune, Fota Island, Carrigaloe and Rushbroke.
• Cork Kent-Midleton Line - Calling at Carrigtwohill. It had been proposed to eventually extend the line to Youghal with intermediate stops at Mogeely and Killeagh.

• Limerick Colbert - Ennis line calling at Sixmilebridge
• Limerick Colbert - Nenagh line calling at Castleconnell and Birdhill. (This is a skeleton service)
• Limerick Colbert - Limerick Junction (for Tipperary town)

• Galway Ceannt-Athenry - Calling at Oranmore