Perpignan has a mainline railway station — the famous one — with TGV connections to Paris (about 5 hours), Montpellier (1.5 hrs), and Barcelona (under 2 hours by the fast Renfe train across the border). The station is a short walk north of the city centre. The AP-7/A9 autoroute runs through from Barcelona to the north; Perpignan is the first French city after the Le Perthus border crossing, and driving from Barcelona takes about 1.5 hours in normal conditions. From Paris by road it is roughly 9 hours — the train is the sensible option.
Perpignan-Rivesaltes Airport, 8 km north of the centre, has low-cost flights from the UK and northern Europe, mainly Ryanair, with seasonal services from several British airports. Outside peak season the connections are limited; check what's running before building a trip around the airport. A taxi or shuttle bus from the airport to the centre takes about 20 minutes. The city centre is walkable from the railway station in 15 minutes, or 5 minutes by tram.