Ingrid Jacoba Visseren-Hamakers (born 3 February 1970) is a Dutch academic and politician of the Party for the Animals (PvdD). She is a professor of environmental policy at Radboud University Nijmegen. Her work focuses on global environmental governance, biodiversity, and sustainability transitions. Since 2023, she has served as a member of the Senate.
Early life and education Visseren-Hamakers was born on 3 February 1970 in Brummen, Gelderland. She studied environmental and social sciences at Utrecht University, and business administration at Erasmus University Rotterdam.
Career Visseren-Hamakers held academic positions at Wageningen University and George Mason University in the United States, before joining Radboud University in 2019. Between 2016 and 2019, she served as coordinating lead author for the global assessment report of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES).
Her political career began in Rotterdam, where she was a member of the IJsselmonde borough council from 1998 to 2002, on behalf of GroenLinks. From 2004 to 2007, she served in the party's executive board. She later joined the Party for the Animals (PvdD), and was elected as a member of the Senate in the 2023 election. On 3 February 2025, she succeeded Niko Koffeman as leader of the PvdD Senate group.
Visseren-Hamakers Group On 10 November 2025, it was announced that Visseren-Hamakers had left the PvdD Senate group, forming her own independent group. The split followed an internal dispute, after Niko Koffeman had resigned his party membership on 21 October 2025, citing dissatisfaction with the party's political direction. He was supported by fellow senator Peter Nicolaï. As a result, Koffeman and Nicolaï continued together under the party banner, while Visseren-Hamakers formed a separate group. Despite the formal split, Visseren-Hamakers is regarded by the Party for the Animals as the sole legitimate representative of the party in the Senate.
Electoral history
+ YearBodyPartyVotesResult.Party seatsIndividual 2004 European Parliament GroenLinks 4 2 2023 Senate Party for the Animals 3 2,112 3
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