Ferry, plane and bus.
If you want to travel by plane there are 2 journeys made from Glasgow International Airport to Islay Airport from Monday - Friday and there is 1 flight on a Saturday and Sunday. The distance is 72 miles and it takes about 40 minutes. It is operated by Loganair / Flybe. You can book your flights through the Flybe website or by phoning the airport on Islay.
Calmac run the ferry service from Kennacraig to either Port Ellen or Port Askaig on Islay. Depending on which timetable is running, there are either 2 or 3 sailings to / from Islay Monday to Saturday and 2 sailings on a Sunday. The journey takes between 2 - 2hrs 30 mins. Sometimes the ferry travels a 4 hour journey to and from Oban, stopping off at Colonsay. To make reservations visit Calmac's online reservation website or phone Calmac direct.
Mundells run the bus service on Islay and travel several different routes on the island between 7am and 6pm Monday - Saturday. There is no bus service on a Sunday.