The standard route is the Bornholmslinjen ferry from Ystad in southern Sweden — fast catamarans cross in about 80 minutes and run several times a day. Ystad is reached by direct train from Copenhagen Central, with a combined train-and-ferry through-ticket available from DSB. The whole Copenhagen-to-Rønne journey takes roughly three and a half hours.
A slower overnight ferry runs direct from Køge (south of Copenhagen) to Rønne, taking about six hours. Rønne Airport is two km south of town with seasonal flights to Copenhagen, Billund and a handful of European cities — DAT runs the year-round service. Ferries arrive at the harbour in central Rønne; the airport is a 10-minute taxi.