Inis Mór is reached by ferry from Rossaveal on the Galway coast, or by small aircraft from Connemara Airport at Inverin.
By ferry: Aran Island Ferries and Island Ferries run regular services from Rossaveal (about 40 minutes from Galway city by shuttle bus, then 40 minutes by ferry) throughout the year, with additional sailings in summer. The crossing takes around 40 minutes in calm conditions and rather longer in rough weather. Ferries also run from Doolin in County Clare in summer, a more dramatic crossing across the mouth of Galway Bay.
By air: Aer Arann Islands (now Aer Árann) runs scheduled flights from Connemara Airport (Aerfort na Mara, Inverin) — a ten-minute flight over the bay. The airport is about 30 minutes west of Galway city. Flights run several times daily, weather permitting; the Atlantic weather can cause cancellations, so ferry backup is worth knowing about.
From Galway city, the ferry-shuttle combination is the standard approach and takes around 90 minutes door to pier. Book ahead in summer, especially for return journeys.