Caitlin Halligan


212 390 9013

Photo of Caitlin Halligan

One of the nation’s leading appellate attorneys, Caitlin Halligan has argued six cases and served as counsel of record for a party or amicus curiae in more than 50 matters before the U.S. Supreme Court. She has handled scores of cases in the federal appellate courts, the New York Court of Appeals, and other state appellate courts. Caitlin has been praised for her “impressive track record” by Chambers USA, named one of the “Top 250 Women in Litigation” by Benchmark Litigation, and recognized as one of Crain’s “100 Notable Women in Law.” She received Legal Aid’s Pro Bono Publico award in 2021 and 2022, Citizen Union’s “Gotham Great” award in 2018, and the Office of the Appellate Defender’s Gould Award for Outstanding Oral Advocacy in 2015.

Caitlin served as Solicitor General for the State of New York from 2001 to 2007, after serving as Deputy Solicitor General. Before that, she served as the first chief of the New York Attorney General’s Internet Bureau, where she developed cutting-edge law enforcement and policy initiatives regarding online consumer fraud, securities trading, and privacy practices. Caitlin also served as General Counsel to the New York County District Attorney’s Office. She currently teaches several classes as a Lecturer on Law at Harvard Law School, including a first-year course on statutory interpretation and administrative law, a workshop on Supreme Court and appellate advocacy, and a seminar on states and public law; next fall, she is teaching a course on state constitutionalism. Caitlin previously taught at Columbia Law School and Georgetown Law Center. She speaks frequently on topics that include appellate advocacy, the Supreme Court’s docket, and the impact of litigation brought by state attorney general offices.

Representative Matters

  • Won unanimous affirmance from the U.S. Court of Appeals for the Second Circuit of a favorable settlement of a nationwide class action lawsuit against Navient, one of the nation’s largest student loan servicers, on behalf of public service workers seeking student loan forgiveness.

  • On behalf of NYC tenant advocacy groups and alongside Legal Aid, won unanimous affirmance from the U.S. Court of Appeals for the Second Circuit of a decision upholding New York’s rent stabilization laws against sweeping constitutional challenges.

  • Selected as interim lead class co-counsel in pathbreaking litigation alleging manipulation of cryptocurrency markets; successfully opposed motion to dismiss.

  • Represents liquidators of Kingate Funds in defending against claims brought by Deutsche Bank Securities Inc. relating to DBSI’s alleged purchase of more than $1.6 billion of Kingate’s claims against the Bernard Madoff estate.

  • Represents Everytown, the national gun violence prevention group, in defending state laws that allow lawsuits against gun industry participants who endanger public safety.

  • Represented National Public Finance Guarantee and MBIA, who insured bonds issued by Puerto Rico and its agencies, in suit against eight major banks to hold them accountable for inequitable conduct that contributed to Puerto Rico’s economic collapse.

  • Won unanimous ruling from the New York Court of Appeals that New York’s consumer protection law should be interpreted broadly to reach a health insurance company’s marketing materials aimed at New York City public employees and retirees.

  • Won unanimous reversal from the Appellate Division, First Department of a trial court decision that had ordered tear-down of newly-constructed high-rise building in Manhattan’s Upper West Side.

  • Served as co-counsel to Manhattan District Attorney’s Office in a landmark Supreme Court case holding that former President Trump must comply with a subpoena for tax records.

  • Served as co-counsel to the former U.S. House of Representatives’ General Counsel in litigating several election-related cases.

  • Won landmark decision from the New York Court of Appeals in Congel v. Malfitano, which set forth standards for dissolution of partnerships under New York law.

  • Successfully represented life settlement investor Lavastone, an AIG affiliate, in a $1 billion RICO, fraud, and breach of contract case against defendants who purchased life insurance policies and sold them to Lavastone at inflated prices.

  • Won precedent-setting victory from the U.S. Supreme Court for New York counties in United Haulers Association v. Oneida-Herkimer Solid Waste Management Authority, which established authority of local governments to enact and implement solid-waste ordinances in the face of the dormant Commerce Clause.

Caitlin has expertise in a broad variety of civil matters, including challenges to federal and state regulatory action, civil procedure, RICO, and securities litigation. She has represented clients before the New York State Attorney General’s Office and litigated numerous challenges to government actions. She has argued both civil and criminal cases before New York’s high court and the State’s intermediate appellate courts on a wide range of constitutional, statutory, and procedural issues.

Caitlin leads the firm’s pro bono efforts and has a very active public interest practice. In addition to the matters described above, Caitlin partnered with the NJ ACLU to bring a class action on behalf of inmates at a federal prison who faced grave health risks as COVID spread throughout their facility. Caitlin is also part of the SGE team leading a lawsuit to help Utah’s residential solar customers get fair payments for power they export to the grid.

Caitlin also has a wide-ranging amicus curiae practice. This fall, she filed briefs in several major cases before the U.S. Supreme Court, including one for water and flood plain managers in a far-reaching Clean Water Act case, another on behalf of the National Academy of Education explaining why race-conscious admissions policies are well-supported by social science research, and a third for the American Bar Association defending the rule of law in federal elections. In 2021, on behalf of the ACLU and NYCLU, she asked the Supreme Court to reverse New York’s lax enforcement of Confrontation Clause protections, and she has filed briefs on other important issues of criminal procedure, habeas corpus, and the death penalty for the ACLU, NACDL, and other organizations. Also in 2021, she filed a brief on behalf of the National Women’s Law Center and 63 additional organizations laying out the pervasive harms of the gender wage gap, in support of the U.S. women’s soccer team’s successful fight for equal pay.

Affiliations & Community Involvement

Caitlin earned her J.D., magna cum laude, from the Georgetown University Law Center and her B.A., cum laude, from Princeton University. She clerked for the Honorable Justice Stephen Breyer of the U.S. Supreme Court and the Honorable Patricia Wald of the U.S. Court of Appeals for the D.C. Circuit. Caitlin is a member of the American Law Institute and a fellow of the American Academy of Appellate Lawyers.  She also serves as chair of the Second Circuit’s Committee on Admissions and Grievances.

  • Georgetown University Law Center (J.D., 1995)
    Magna cum laude, Order of the Coif, Georgetown Law Review: Managing Editor; Olin Fellow in Law and Economics
  • Princeton University (B.A., 1988)
    Cum laude

  • Maryland and New York Bars
  • Supreme Court of the United States
  • United States Courts of Appeals: First Circuit, Second Circuit, Third Circuit, Fourth Circuit, Fifth Circuit, Sixth Circuit, Ninth Circuit, Eleventh Circuit, and Federal Circuit
  • United States District Courts: Eastern District of New York, Southern District of New York