Mikkeli is well-connected by train from Helsinki. The journey on the direct service takes around two hours; trains run frequently throughout the day. The railway station is central and within easy walking distance of the main sights.
By car, Mikkeli is about 230 kilometres from Helsinki via the E75 motorway, roughly a two-and-a-half-hour drive. The town also has a small airport (IATA: MIK) about four kilometres west of the centre, but scheduled flights are limited — the train is the practical choice for most visitors.
Bus services connect Mikkeli with surrounding towns and with Savonlinna (about 80 kilometres east), which makes it feasible to combine the two as part of a wider Finnish Lake District tour.