Ærø is small enough that most visitors leave their car on the mainland. A bicycle covers the island comfortably — Ærøskøbing to Marstal is about 13 km, Ærøskøbing to Søby about 15 km. Bike rental is available at all three ferry harbours and at most accommodations, with both standard and electric bikes.
A local bus (route 790) loops the island roughly every hour in summer, less often in winter, connecting the main towns and several smaller villages. The buses are free to ride as part of an island-wide initiative funded by the municipality. For a car, the ferry takes vehicles but the small island roads and quiet rhythm of the place really suit two wheels better.