Cahill Logo

William M. Hartnett

William M. Hartnett

Senior Counsel

Download vCard

Cahill Gordon & Reindel LLP
32 Old Slip
New York, NY 10005



  • Fordham University School of Law, J.D., 1979, cum laude
  • Rider University, B.A., 1976, cum laude


  • New York

Bill Hartnett has advised leading commercial and investment banking firms and public and private companies in a broad range of domestic and cross-border capital markets and lending transactions for more than 30 years.

Bill advises clients on leveraged bank financings, out-of-court restructurings, mergers, acquisitions and debt and equity-linked securities offerings. Bill is a former partner and served as Chairman of the firm for 18 years.

Lauded in Chambers as having “the respect of Wall Street,” Bill serves as outside corporate counsel to a number of public and private companies and has extensive experience representing special committees of the boards of directors of public companies in connection with strategic transactions and related compliance matters.

"William combines commercial instinct and technical ability." – Chambers USA

Bill also advises companies on acquisitions, divestitures, joint ventures and related financings.  He has notable experience with companies in many industries, particularly in media, pharmaceuticals, telecommunications, technology and gaming.

Since his representation of the financing sources in the historic buyout of RJR Nabisco in 1989, Bill has been at the forefront of emerging financing structures for many prominent domestic and international financing transactions such as the buyouts of Dell, Nielsen, SunGard, HCA, Harrah's and First Data. He is consistently named among the top lawyers globally and nationally for capital markets and banking transactions by a variety of industry publications including: Chambers Global, Chambers USA, the IFLR 1000: Guide to the World's Leading Financial Law Firms, The Legal 500, Lawdragon 500's Hall of Fame and Leading Dealmakers in America guide, Who’s Who Legal and Global Counsel. In 2010, Bill was the recipient of the Leonard F. Manning Achievement Award from Fordham Law Review.  

Bill joined Cahill following his graduation in 1979 from Fordham Law School, cum laude, where he was a member of the Fordham Law Review. He earned his undergraduate degree at Rider University in 1976, cum laude.