John McGinley operates a bus from Dublin to Donegal hourly. Tickets cost $19 - $28 and the journey takes 3 h 25 min. Bus Eireann also services this route every 3 hours. Alternatively, Aer Lingus flies from Dublin to Donegal twice daily.
How to get from Dublin to Donegal
From Rotunda, Hugh Lane Galllery bus to Letterkenny, Mr. Chippy Chip Shop then taxi to Donegal. 3 h 45 min 54€. From Dublin drive to Donegal. 3 h 9 min 35€. From The 3Arena line 702 bus to Dublin airport, fly to Donegal airport, then taxi to Donegal. 3 h 2 min 99€.