| Honorific-Prefix: | Her Excellency |
| Mariëtte Hamer | |
| Office: | Chairwoman of the Social and Economic Council |
| Term Start: | 10 September 2014 |
| Term End: | 1 April 2022 |
| Predecessor: | Wiebe Draijer |
| Successor: | Kim Putters |
| Office1: | Leader of the Labour Party in the House of Representatives |
| Term Start1: | 22 January 2008 |
| Term End1: | 17 June 2010 |
| Predecessor1: | Jacques Tichelaar |
| Successor1: | Job Cohen |
| Office2: | Chairwoman of the Labour Party |
| Term Start2: | 5 September 2000 |
| Term End2: | 16 March 2001 Ad interim |
| Leader2: | Wim Kok |
| Predecessor2: | Marijke van Hees |
| Successor2: | Ruud Koole |
| Office3: | Member of the House of Representatives |
| Term Start3: | 19 May 1998 |
| Term End3: | 10 September 2014 |
| Birthname: | Mariëtte Iris Hamer |
| Birth Date: | 1958 6, df=y |
| Birth Place: | Amsterdam, Netherlands |
| Nationality: | Dutch |
| Party: | Labour Party (since 1984) |
| Residence: | Maassluis, Netherlands |
| Alma Mater: | University of Amsterdam (Bachelor of Arts, Master of Arts) |
| Occupation: | Politician · Civil servant · Trade Union leader · Teacher · Activist |
Mariëtte Iris Hamer (born 7 June 1958) is a Dutch politician and trade union leader serving as commissioner for combating inappropriate behavior and sexual violence since 2022. A member of the Labour Party (PvdA), she was its leader in the House of Representatives from 2008 to 2010.
A native of Amsterdam, Hamer studied linguistics at the University of Amsterdam. She is a co-founder and was chairwoman of the Dutch Student Union (LSVb); she later worked as an educator and at the Ministry of Education, Culture and Science.
Hamer served as a member of the House of Representatives from 19 May 1998 and 10 September 2014. From 22 January 2008 to 17 June 2010 she was parliamentary leader; she was succeeded by former Amsterdam Mayor and party leader Job Cohen, who had just been elected to the House of Representatives. She focused on matters of labour economics, day care and emancipation. In the past she also focused on matters of education, social affairs. Hamer also was party chair in an interim capacity from 5 September 2000 until 16 March 2001.
Since 10 September 2014 Hamer has been a Crown-appointed member and Chairwoman of the Social and Economic Council (SER). She was nominated to the position by Lodewijk Asscher, Minister of Social Affairs and Employment; King Willem-Alexander of the Netherlands validated the appointment. She succeeded Wiebe Draijer, who resigned from office following his appointment as CEO of the Rabobank.[1] In the House of Representatives Hamer was succeeded by Henk Leenders.[2]
In 2022, Hamer was appointed by the government of Prime Minister Mark Rutte as commissioner for combating inappropriate behavior and sexual violence, a new role in which she is tasked with coming up with a plan to tackle sexually inappropriate behavior and sexual violence.[3] At the request of Minister of Education Robbert Dijkgraaf, she investigated how such behavior could be mitigated at institutions of higher education. Hamer concluded they should step up their efforts, saying the behavior is particularly prevalent at those ages. She recommended colleges and universities to provide mandatory sex education, to hire ombudsmen, and to better inspect student associations.[4]