Lars Jacob Jack Vreeswijk was a Swedish ballad singer, song lyricist and composer. The son of troubadour Cornelis Vreeswijk, he followed in his father's footsteps and released three albums of his own, often singing his father's songs. He was usually accompanied by guitarist Love Tholin.
In summer 2006, Jack Vreeswijk appeared in a biographical musical show about his father Från James Dean till Nationalskald, on Lundsbrunns Health Resort in Götene. The screenplay was written by him and he also played the lead role as the older Cornelis. The acting was interspersed with songs.
Vreeswijk composed music for a film about Cornelis Vreeswijk's life, and produced eight of the tracks on Hans-Erik Dyvik Husbys' album I ljuset av Cornelis. In 2009, he released a tribute album to his father's music titled Jack Vreeswijk sjunger Vreeswijk.