The Maynooth commuter line will now connect to Aircoach routes 700 and 700X from Drumcondra.
An integrated ticketing system has been launched by Iarnród Éireann and Aircoach.
The partnership allows passengers to book a single ticket that includes both rail travel and an Aircoach transfer to the airport via the Iarnród Éireann website.
The Maynooth commuter line will now connect to Aircoach routes 700 and 700X from Drumcondra.
The introduction of the partnership with Aircoach means all Intercity services terminating in Dublin now have a connection to Dublin Airport and all services terminating in Cork have a connection to Cork Airport.
It also means passengers can travel on Intercity services from Sligo and Rosslare Europort.

Taxi Driver Protest Suspended Pending Outcome Of Talks
Lights Could Make Anti-Social Behaviour Worse: Council Says No To Security Lighting At Kilcock Playground
BREAKING: Green Light For €1.3bn Drainage Scheme Serving Kildare After Court Agreement
Kildare Man Nigel Cullen Awarded With National Bravery Award After Saving Young Man From House Fire
Council Diverts €17K Carbury Castle Resoration Funding To Christmas Lights - Maynooth Gets Lion's Share
Lakeside–Dara Park Redevelopment: Newbridge Residents Urged To Take Part In Survey
Irish Troops Come Under "Small-Arms Fire" In Lebanon
€17,000 Paid Out For Pothole Damage In Kildare - But Some Claims Now Deemed ‘Act Of God’