Arendal is on the Sørlandsbanen railway line, which runs between Oslo and Stavanger. The station is in Nelaug, about 20 km from the town centre, with a connecting bus. The journey from Oslo takes around three hours by train; from Kristiansand it is less than an hour.
By road, Arendal is accessible via the E18 motorway along the southern coast. The drive from Oslo takes about three hours in normal traffic. In summer, the coast road (Route 42) offers a more scenic alternative west of Kristiansand.
There is no major airport nearby. Kristiansand Airport is the closest, with domestic connections to Oslo.