Athlone is on the main Dublin–Galway rail line, with frequent services from both cities. The journey from Dublin Heuston takes about 80 minutes; from Galway about an hour. The station is on the east side of town, a ten-minute walk from the castle.
By bus, Citylink and Bus Éireann both serve the Dublin–Galway route via Athlone. Driving from Dublin takes about 90 minutes on the M4/M6; from Galway about an hour on the same road.