Marianne Louise Thieme (born 6 March 1972 in Ede) is a Dutch animal-rights activist, author and former politician best known for co-founding the Party for the Animals (PvdD). Trained in law, she combined grassroots campaigning with parliamentary work and served as the party's political leader from its early years until 2019. Thieme was a member of the Dutch House of Representatives (the Second Chamber) and acted as the PvdD's parliamentary leader during her tenure.

Background and education

Thieme was born in the town of Ede (Ede) and studied law at Erasmus University Rotterdam (Erasmus University). Her legal education informed a pragmatic approach to political advocacy: framing animal protection and environmental issues in terms of legislation, regulation and public policy. She is publicly known as a vegan and as a member of the Seventh-day Adventist Church (SDA), positions that have informed her public profile and personal choices.

Political career and activity

In 2002 Thieme helped establish the Party for the Animals as a political vehicle focused on animal welfare, environmental protection and sustainability. The party set out to advance the rights and interests of animals through the parliamentary process as well as to push for broader changes to agriculture, food systems and biodiversity policy. Thieme served as party chair in the early years and later as the party’s political and parliamentary leader. In 2019 she stepped down and was succeeded by Esther Ouwehand.

Policy focus and methods

  • Animal welfare and rights: promoting higher welfare standards and legal protections for animals (animal rights).
  • Food and agriculture: advocating for sustainable farming, reduced intensive livestock production and policies that encourage plant-based diets.
  • Environment and biodiversity: integrating conservation and climate concerns into legislation and public debate.

Thieme combined parliamentary proposals and debates with public outreach, writing and campaign work. As an author and speaker she sought to translate ethical arguments about animals into concrete policy proposals and to broaden public discussion about consumption, farming and the humane treatment of animals.

Impact and legacy

Under Thieme’s leadership, the Party for the Animals brought animal protection into mainstream Dutch politics and drew international attention as part of a wider movement that places animal welfare on national agendas. The party’s presence in parliament pushed other parties to respond to questions about farming practices, animal welfare standards and the environmental impacts of food production. Even after leaving political office, Thieme remains associated with animal-rights advocacy and public writing.

For further information about the party and related initiatives see Party for the Animals and resources on animal-rights advocacy (animal rights), or background on Thieme’s educational and personal profile via Erasmus University and community references (Seventh-day Adventist, Ede).