[2] He attended Het Hogeland College [nl] in Warffum and studied sociology at the University of Groningen, while working at a cardboard factory.

In September 2010, Dijk became a member of the municipal council of Groningen as a temporary replacement for the departing Peter Verschuren [nl].

In April 2023, Dijk joined the House of Representatives after Maarten Hijink vacated his seat, becoming the party spokesperson for health.

[7] Dijk succeeded Lilian Marijnissen as leader of the SP when she stepped down in December 2023 due to disappointing election results.

[10] In January 2025, Dijk announced his engagement to Mechteld, a fellow SP member whom he had met twelve years earlier.