Diederik or Diderik is a male given name, the Dutch / Low Franconian and Low German form of Theodoric (Dietrich in High german). In North Germanic languages, the native form would be Tjodrik, but Diderik and Didrik has been loaned from Low German and is now a common name in Norway.
Common short forms of the name are Dirk, Dirck, Dik, Derek and Derick.
People with the name include: