John C. Calhoun

John Calhoun is a member of Choate's Litigation Department.  Mr. Calhoun’s practice is focused on litigating complex civil cases in federal and state court.  He is experienced in handling disputes involving intellectual property, private equity contracts, private schools, and internal company whistleblowers.  Mr. Calhoun graduated from Yale Law School, where he served as an Editor of the Yale Law Journal and Managing Editor of the Yale Journal of International Law.  Prior to law school, he served as a Marshall Scholar at the University of Oxford (UK), and as a Fulbright Scholar.  He has also advised presidential, gubernatorial, and congressional administrations and campaigns on a range of legal and policy issues.

Practice Focus

Litigation:  assists in representation of leading corporations and financial institutions in complex commercial litigation.

Representative Engagements 

  • Prevailed at summary judgment (including for costs) while representing a major private equity firm in a suit filed by the founder of an acquired company.
  • Won at trial while representing an international insurer in successful action to rescind $25 million product contamination insurance policy based upon policyholder’s material misrepresentation of facts.
  • Reached favorable settlement for law firm in a legal malpractice suit filed by a former client.
  • Reached favorable settlement for automotive parts manufacturer seeking indemnification from Chinese suppliers.
  • Trial counsel for Momenta Pharmaceuticals in patent infringement litigation relating to innovative methods of processing therapeutic polysaccharides. (Momenta Pharm., Inc. v. Amphastar Pharm., Inc. et al., D. Mass. , Fed. Cir.)
  • Counsel for Foundation Medicine in proceedings related to innovative comprehensive genomic cancer assays using next generation sequencing. (Foundation Medicine, Inc. v. Guardant Health, Inc.)
  • Counsel in trade secret misappropriation lawsuit brought against Dicerna Pharmaceuticals. (Alnylam Pharmaceuticals, Inc. v. Dicerna Pharmaceuticals, Inc., MA)
  • Extensive representation of private independent schools in investigating and remediating allegations of sexual misconduct.
  • Represented and reached favorable settlement for large US bank in an OSHA-proceeding brought by an internal company whistleblower.
  • Investigated internal company whistleblower complaint for international insurer.

Publications and Presentations

Professional and Community Involvement

Mr. Calhoun is a member of the Boston Bar Association and the American Bar Association.  He is a member of multiple business and charitable boards, including the Connecticut Policy Institute, Give a Summer, and Firoz Academy.  Through Choate’s pro bono program, Mr. Calhoun also represents special needs children to help them secure appropriate educational services.

Education & Credentials

Yale Law School
JD, 2015

Editor, Yale Law Journal

Managing Editor, Yale Journal of International Law

Oriel College, University of Oxford
MSc, 2012, with honors

University of York
MA, 2011, with honors

University of Richmond
BA, 2009, summa cum laude, Phi Beta Kappa 


U.S. Court of Appeals, First Circuit

District of Massachusetts