John O’Neil’s legal knowledge, business savvy, and leadership of complex transactions have earned him a reputation as a global leader in private equity fund matters. John heads the Investment Funds Practice Group, the Firm’s leading-edge global platform that provides innovative and bespoke legal strategies to sponsors and funds of all kinds. John is also a member of the Firm's Executive Committee.

John has been recognized by Chambers Global, Chambers USA, IFLR 1000, Legal 500, and Who’s Who Legal where he was described as a “‘phenomenal lawyer,’ acknowledged for his strong track record representing large sponsors” and being “extremely smart and creative”. Founders look to John as a valued business partner and a global thought leader on identifying market trends, creating and executing plans across AUM, product line and geographical expansion.

As the advisor of choice of some of the world’s most sophisticated and dynamic investment funds, John has guided clients for over two decades through a myriad of operational issues as well as extraordinary events involving private investment funds and their sponsors. His breadth of experience includes helping clients successfully navigate “key person” events, investor defaults, spin-outs, and other significant transactions. John is a founding member of the Firm’s Investment Funds Crisis Management Group, which guides investment fund sponsors, advisory boards, and other market participants through some of their most challenging situations.

John’s long-standing industry relationships and deep understanding of the investment funds landscape are game-changers for the Firm’s clients. Who’s Who Legal notes that he “has one of the broadest, best understandings of what is happening in the market.” John is a founding member of the New York City Investment Funds Society, which regularly convenes the leading American lawyers who advise sponsors. He is an in-demand speaker on the private investment industry, addressing audiences at the International Bar Association conference, New York Private Equity Network, and the New York City Bar Center for CLE.

John received his J.D. from Northwestern University School of Law and is a graduate of University of Wisconsin-Madison. He is admitted in New York, Massachusetts and Illinois.

Representative Clients

50 South Capital, Audax Group, Basin Oil & Gas, Blue Sage Capital, Bruckmann, Rosser, Sherrill & Co., Caltius Capital Management, CHS Capital, Clearlake Capital Group, ClearLight Partners, Coller Capital, Coral Reef Capital, Dunes Point Capital, Fundtech Holdings, GI Partners, GLP, Greenbriar Equity Group, GTCR, H.I.G. Capital, HighBridge Equity Partners, Kinderhook Capital, Lake Partners, Landmark Partners, Newstone Capital Partners, Old Ironsides Energy, Paul Capital Partners, Pegasus Partners, Perceptive Advisors, Periphas Capital, Rhône Capital, Round Hill Music, Siris Capital Group, SK Capital, Softbank, Summit Partners, Sycamore Partners, TeleSoft Partners, Triton, TZP Capital Partners, Varsity Management Company, Veritas Capital, Vestar Capital Partners, Vista Equity Partners, Water Street Healthcare Partners, White Oak Global Advisors, Wind Point Partners and Wynnchurch Capital, York Capital Management.


Thought Leadership


John speaks frequently on matters relating to private investment funds. Select recent public speaking engagements include:

  • Panelist, Thomson Reuters, The 34th Annual Federal Securities Institute
  • Panelist, General Partner Succession Planning, Kellogg Private Equity And Venture Capital Conference
  • Speaker, PEAI Private Equity CFO/COO Exchange & Roundtable
  • Speaker, New York Private Equity Network, Private Equity GP / LP Fund Terms
  • Speaker, Practising Law Institute’s 14th Annual Private Equity Forum
  • Speaker, International Bar Association’s 14th Annual International Conference on Private Investment Funds
  • Speaker, Kirkland & Ellis LLP, Registered Adviser Seminar & CCO Summit
  • Speaker, Columbia Business School Alumni Club of New York, Private Equity Allocation in an Uncertain Economy
  • Speaker, Private Equity CFO Association, General Partner Structuring (Succession Planning, Division of Economics and Tax Considerations)
  • Panelist, Kirkland & Ellis LLP, Structuring and Negotiating LBOs Seminar
  • Speaker, New York Private Equity Network, Private Equity GP / LP Fund Terms
  • Panelist, Maples and Calder, Maples FS, 3rd Maples Investment Funds Forum
  • Speaker, Kirkland & Ellis LLP, Private Fund Manager Advisers Act Registration Seminar
  • Speaker, New York City Bar Center for CLE, After the Dust Settles: The Changing Landscape for Private Investment Funds & Their Managers
  • Speaker, International Bar Association’s 21st Annual Conference on the Globalisation of Investment Funds
  • Speaker, New York City Bar Center for CLE, The Impact of the Current Environment on Private Investment Funds & Their Managers
  • Moderator, CFA Society of Washington and Wharton Private Equity Partners LP/GP Roundtable
  • Moderator, Duke Private Equity Club PE Conference


Kirkland & Ellis Pro Bono Service Recipient

Listed in:

The Best Lawyers in America 2019, in Private Funds / Hedge Funds Law 

“Market Leader,” IFLR1000

“World’s Leading Lawyers for Business,” Chambers Global

“America’s Leading Lawyers for Business,” Chambers USA

“Guide to the World’s Leading Investment Funds Lawyers,” Legal Media Group

“Who’s Who Legal: The International Who’s Who of Private Funds Lawyers,” Law Business Research Ltd.

“Leading Lawyer,” The Legal 500 United States

Memberships & Affiliations

Member of National Board for Susan G. Komen

Member of the Private Investment Funds Forum, a group comprising New York City attorneys practicing extensively in the private funds area

Member of the Committee on Private Investment Funds of the Association of the Bar of the City of New York

International Bar Association, Investment Funds Sub-Committee

Firm Activities

Member, Executive Committee


Admissions & Qualifications

  • Massachusetts
  • New York
  • Illinois


  • United States Court of Appeals for the Seventh Circuit1998


  • Northwestern Pritzker School of LawJ.D.cum laude1998
  • University of Wisconsin-MadisonB.B.A., Management Information Systems1991