Paderborn is located in the heart of Germany and can be reached easily by air, car, and rail. You will find all arrival information on the city's website (see headline DIRECTIONS).
The closest airport is the regional airport Paderborn/Lippstadt (PAD) which offers regular connections to e.g. Munich. Other nearby airports are Hannover (HAJ), Dortmund (DTM), Köln/Bonn (CGN), and Düsseldorf (DUS).
From Paderborn/Lippstadt you may take the bus routes S60 or 460 to Paderborn main station or a taxi. The airports Hannover, Köln/Bonn, and Düsseldorf are directly connected to a train station from which you can travel with the Deutsche Bahn to Paderborn main station.
If you want to travel by train, you likely arrive at Paderborn main station. While there are a few ICE and IC connections directly stopping in Paderborn, you typically use a intercity connection (ICE, IC) to Kassel-Wilhelmshöhe, Hamm, Bielefeld, or Hannover and continue with regional trains to Paderborn. For more details, e.g., fares or routes, we refer to the webpage of the Deutsche Bahn.
Paderborn is close to the motorway A33 exit Paderborn Zentrum (in direction to Paderborn). The motorway A33 is connected to the motorways A2 and A44. Additionally, you may reach Paderborn via the B1, B64, B68 or B480.