Jeanette Mary Fitzsimons, CNZM (born 17 January 1945) is a New Zealand politician and environmentalist. She was the co-leader of the Green Party of Aotearoa New Zealand from 1995 to 2009, and was a Member of Parliament from 1996 to 2010.
Fitzsimons' first entry into politics was as a candidate for the Values Party, an early environmentalist based political party. She was its energy spokesperson from 1977 to 1982, and stood as a candidate in the 1978 election and the 1981 election. When the Values Party merged with a number of other groups to form the modern Green Party, Fitzsimons became an active member of the new organization.
When the Green Party joined with several other left-wing parties to form the Alliance, Fitzsimons became co-deputy leader (with Sandra Lee-Vercoe holding the other deputy leader position). In the 1993 election, Fitzsimons unsuccessfully contested the Hauraki electorate under the Alliance banner. In 1995, she became co-leader of the Green Party (which remained within the Alliance). In the 1996 election, the first to be conducted under the new MMP electoral system, Fitzsimons was placed third on the Alliance party list. The Greens contested the 1999 election as an independent party, with Fitzsimons and Rod Donald serving as co-leaders. Fitzsimons was placed first on the party's list.
In the 2002 election, Fitzsimons was defeated in Coromandel, placing third. Fitzsimons remained in Parliament as the highest-ranked candidate on the Green Party's list, and remained co-leader of the party until 2009, with probably the highest public profile of any Green MP. She became the spokeswoman for the Labour government's solar heating promotion initiatives following the 2005 election.
In February 2009, Fitzsimons announced that she would step down as party co-leader at the party's annual conference, and she was replaced by Metiria Turei on 30 May 2009. Fitzsimons left Parliament on 11 February 2010, and was replaced by the next candidate on the Green Party list, Gareth Hughes. On 7 June 2010, Fitzsimons was awarded a Companion of the New Zealand Order of Merit in the Queen's Birthday Honours List.
At the time, she intended to serve out the remainder of her term as a Member of Parliament.