Bratislava Airport (BTS) is about 9 km northeast of the city centre, served by Ryanair and a handful of other budget carriers. Vienna Airport (VIE), about 60 km away in Austria, is far better connected and worth considering — a bus runs between Vienna Airport and central Bratislava in around 1 hour (from €5–10 one-way).
By train, Bratislava is connected to Vienna (1 hour, several trains daily), Budapest (2.5 hours), Prague (4 hours), and Košice (4.5 hours). The main train station, Bratislava hlavná stanica, is a 20-minute walk or short tram ride north of the old town.
River boats run between Vienna and Bratislava in the summer months (Twin City Liner), a scenic and comfortable alternative to the train.