[5] She attended School of the Holy Child in the village of Old Westbury on Long Island in New York, and graduated from Trinity College in Hartford, Connecticut in 1988.

She later became the executive director of the New York City Anti-Violence Project, and was appointed a member of the NYC Police/Community Relations Task Force by then-Mayor Rudy Giuliani.

[12] Quinn also "shepherded" a ban on indoor smoking at commercial establishments through the City Council; the bill passed 42–7.

[2][3] Preceding the controversial lecture by Iranian President Mahmoud Ahmadinejad at Columbia University in 2007, Quinn wrote to the school requesting that his invitation to speak be withdrawn due to his support of state-sponsored terrorism and hate speech, the latter particularly with regard to the Holocaust.

[22] Under Quinn's leadership, the New York City Council led efforts to make Greenmarkets accept food stamps.

[24] On December 26, 2012, Quinn wrote a letter to President Obama formally requesting that he commute Jonathan Pollard's lifetime sentence for providing classified information to Israel.

Near tears, she added: 'This is literally a moment when people can stand up and say that everybody's family matters, that everybody's home is a blessed place and that everybody has the same rights.

'"[32] On July 28, 2012, Quinn sent a letter demanding that the president of NYU end its relationship with Chick-Fil-A, because of the stance of the company's CEO, Dan Cathy, against same-sex marriage.

[33] According to New York, "[for] years, Quinn opposed term limits, a position that helped her get elected speaker by fellow Council members in 2005.

Gotbaum declared herself a victim of "political payback" because of her opposition to the changes in the term limits law,[38] a notion Quinn claimed was "ridiculous".

All five candidates for Public Advocate showed up at City Hall in June to protest the move,[39] and in 2010 New Yorkers again voted overwhelmingly to limit politicians to two consecutive terms.

)[42] Widely viewed as Bloomberg's heir apparent,[43] Quinn was considered the early frontrunner in the nine-candidate race for the Democratic nomination.

[54] In October 2014 Quinn stumped for the Women's Equality Party established by New York Governor Andrew Cuomo in July 2014.

Quinn said she was hoping to continue the good work of WIN's previous longtime leader, Bonnie Stone, and use a holistic approach to help women facing domestic violence, eviction, and other issues.

[59][60] Before accepting the position at WIN, Quinn fought against a homeless shelter planned for her own neighborhood of Chelsea.

[64][65][66] In 2019, Quinn and WIN drew criticism from the press (including a masthead editorial in The New York Daily News) for two contracts to operate homeless shelters in South Park Slope, Brooklyn.

[67] The allegations, verified by multiple journalists, included that the contracts contained up to $89 million of unexplained and apparently inflated costs.

[71] Though Quinn was designated an elector in the 2020 presidential election,[72] Manhattan Borough President Gale Brewer served as her alternate.