Previously, she served as advisor to the former Deputy Chief Minister of Delhi, Manish Sisodia, primarily on education, from July 2015 to 17 April 2018.

Although she comes from a family of Punjabi background, just before the 2019 Indian general election, she dropped 'Marlena' from her surname to “not want to waste time in proving her identity.”[8][9][10][11] She was given the middle name Marlena by her parents.

[5] She was closely involved with the Jal Satyagraha in Khandwa district of Madhya Pradesh 2015 and provided support to the AAP leader and activist spearheading the campaign Alok Agarwal during the historic protests, as well as during the legal battle that ensued.

[18] She contested from the East Delhi (Lok Sabha constituency) as an Aam Aadmi Party candidate for the 2019 Indian general election.

[25] On 17 September 2024, she was named as the Chief Minister of Delhi in a meeting of Aam Admi Party MLAs at the residence of Arvind Kejriwal.

[27] Even though Aam Aadmi Party lost the 2025 Delhi Legislative Assembly election, Atishi again won from her constituency Kalkaji, defeating BJP's contender Ramesh Bidhuri by 3521 votes.

On March 15, 2019, Atishi and three other party leaders were summoned to court in response to a defamation case filed by the Delhi BJP's vice-president, Rajeev Babbar.