She has represented the electorate of Melbourne in the Parliament of Victoria since 2014 as a member of the Victorian Greens and been the party's leader since April 2024.

[2] She was a recipient of the Young Environmentalist of the Year Award in 2009 and director of the Australian Youth Climate Coalition between 2011 and 2012.

[7] From 2007 to 2009, she was employed as a policy adviser in the Victorian Department of Premier and Cabinet,[7] working on the Brumby Labor Government's climate change strategy and Green Paper.

[8] Sandell worked for the Australian Youth Climate Coalition (AYCC) between 2009 and 2012, serving as general manager before becoming the group's National Director.

[10] Sandell went on to win the seat of Melbourne at the 2014 election, defeating the Labor incumbent, Jennifer Kanis.