Leuven is one of the most accessible cities in Belgium. Its position between Brussels and Liège on the main east-west rail corridor means it is connected to the rest of the country and to international networks with unusual directness.
By train is by far the best way to arrive. From Brussels Centraal or Brussels-Midi, trains to Leuven run every 15 minutes and take around 25 minutes. From Brussels Airport (Zaventem), there is a direct train to Leuven every 30 minutes taking about 15 minutes — shorter than the journey into Brussels itself. From Liège, trains take about 45 minutes. Leuven station is well-positioned, about 10 minutes' walk from the Grote Markt.
By car, Leuven sits on the E40 motorway connecting Brussels to Liège and Cologne. The city centre operates a low-emission zone (LEZ) and parking within the centre is limited and expensive. There are several large park-and-ride facilities on the edges of the city; using one of these and walking or cycling in is far more practical than driving to the centre.
Brussels Airport is the obvious international gateway, with a direct train connection making the transfer unusually simple. The airport is, in effect, closer to Leuven than to the centre of Brussels.