Gavan W. Duffy Gideon


  • Harvard Law School, J.D., magna cum laude, 2020
    • Executive Editor, Harvard Law Review, 2019-2020
  • Yale University, B.A., 2014
    • Yale Journalism Scholar
    • Managing Editor, Yale Daily News, 2012-2013


  • Law Clerk, Justice Elena Kagan, Supreme Court of the United States, 2022-2023
  • Law Clerk, Judge Cornelia T.L. Pillard, U.S. Court of Appeals, District of Columbia Circuit, 2020-2021


  • 2021, New York
  • 2024, District of Columbia

Gavan Gideon represents both plaintiffs and defendants in complex civil litigation at the trial and appellate levels.

Gavan rejoined Kellogg Hansen as an associate in 2023 after serving as a law clerk for Justice Elena Kagan of the U.S. Supreme Court. Prior to joining the firm, Gavan clerked for Judge Cornelia T.L. Pillard on the U.S. Court of Appeals for the D.C. Circuit. Gavan graduated magna cum laude from Harvard Law School, where he was an Executive Editor on the Harvard Law Review. He earned his undergraduate degree in English from Yale University and served as a managing editor of the Yale Daily News. Before law school, Gavan worked in news media as a researcher focused on foreign affairs.

Publications and Speaking Engagements

  • Note, Nondelegation’s Unprincipled Foreign Affairs Exceptionalism, 134 Harv. L. Rev. 1132 (2021)
  • The Supreme Court, 2018 Term — Leading Cases:  Gamble v. United States, 133 Harv. L. Rev. 312 (2019)