[5] From 2004, until she took parliamentary office in 2008, she worked for Amnesty International as Campaign Manager for South Australia and the Northern Territory.

[10] Hanson-Young was a candidate for the South Australian Legislative Council in the 2006 state election, ranked fourth on the Greens' ticket.

[16] Public reaction on the matter was divided, and ignited a debate on accommodating children and their careers in the workplace.

[20] Following the resignation of Australian Greens leader Bob Brown in 2012, she was again nominated for the deputy leadership but lost by an undisclosed margin to Adam Bandt.

In December 2013, Hanson-Young, along with Senators Louise Pratt (ALP) and Sue Boyce (LNP) established a cross-party working group on marriage equality.

[23] Hanson-Young won a further six-year senate term in the 2019 federal election, with her party receiving 10.9% of first preference votes, as well as a 5.03-point swing in her favour.

[29][30][31] On 14 August 2018, the Greens moved a motion in the Senate to censure Leyonhjelm for his remarks against Hanson-Young which passed 30–28.

[37] Hanson-Young was married to former local government councillor Zane Young; the couple divorced in 2011.