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Jillian Williams’ practice focuses on complex civil litigation, appellate matters, and participation in agency rulemaking activities, with a particular emphasis on the Clean Air Act (CAA). They also maintain an active pro bono practice with an emphasis on voting, civil rights, and civil liberties litigation.

Jillian received their law degree from Columbia Law School where they served as the Symposium & Book Review Editor of the Columbia Law Review; Director of the Harlan Fiske Stone Moot Court Competition; and as an extern for the Honorable Robert D. Sack of the U.S. Court of Appeals for the Second Circuit.

Jillian was also a recipient of the Justice John Paul Stevens Fellowship, as well as the Campbell Award, which is presented by the Columbia Alumni Association to a graduating student at each school who shows exceptional leadership and school spirit. 

Prior to rejoining the firm, Jillian served as a law clerk to the Honorable James L. Cott of the U.S. District Court for the Southern District of New York.


  • Consumer products manufacturer in numerous individual actions alleging personal injury, wrongful death, and consortium claims.
  • Pharmaceutical manufacturers in a successful APA challenge to a CMS and HHS rule under Medicaid regarding co-pay accumulator programs and financial assistance to patients.
  • Biofuels producers in D.C. Circuit litigation challenging EPA’s final rule setting cellulosic biofuel volumes for purposes of the annual Renewable Fuel Standards (RFS) Rule under the Clean Air Act.



  • J.D., Columbia Law School, 2021, Campbell Prize
  • A.B., with distinction, Literature and Global Cultural Studies, Duke University, 2015


  • District of Columbia

Government & Military Service

  • Legal Extern, U.S. Attorney's Office for the Southern District of New York
  • Legal Intern, Public Integrity Section, U.S. Department of Justice, Criminal Division


  • U.S. District Court, Southern District of New York, The Honorable James L. Cott