[5] In April 2014, Samantha Ratnam explained in The Indian Sun, an online publication for the Australian-Indian community how she is a product of diaspora and her motivations for entering politics.

[13] Ahead of the 2016 federal election the Greens preselected Ratnam to stand in the Division of Wills, where the sitting Labor MP Kelvin Thomson was retiring.

[15][16] Ratnam filled the vacant Legislative Council seat of former Victorian Greens leader Greg Barber, who announced his retirement from politics on 28 September 2017.

[17] On 12 October 2017, prior to having officially filled Barber's seat, Ratnam was appointed as leader of the Victorian Greens, becoming the first woman to lead the party at a state level.

[20] Ratnam was re-elected in the Northern Metropolitan region at the 2018 state election, though her four party colleagues failed to win back their seats and she became the only Greens member of the Legislative Council.

As a social work PhD student, Ratnam contributed to a number of peer-reviewed research papers and academic books, including: