O’Melveny Worldwide

Shannon Barrett concentrates his practice on ERISA-related litigation and on providing advice relating to Title I of ERISA. He has been involved in litigating a broad range of ERISA matters at both the trial and appellate levels, with a particular focus on fiduciary issues. In addition to his litigation practice, Shannon has assisted clients in responding to regulatory investigations and has counseled clients, including financial institutions and plan sponsors, on ERISA issues such as fiduciary structure, fee disclosure, and compliance with ERISA’s prohibited transaction provisions. Shannon also has advised independent fiduciaries in their representation of employee benefit plans’ rights in connection with ERISA and securities settlements.

Shannon is a frequent thought leader on ERISA-related topics and serves as the co-editor of the ERISA Litigation Reporter. He is recognized by Chambers USA and Legal 500 in the ERISA Litigation (Nationwide) category.

  • Defended affiliates of Fidelity Investments in a series of cases challenging 401(k) plan fees, including Columbia Air Services, Inc. v. Fidelity Management Trust Co. and Hecker v. Deere & Co., which were dismissed on all claims 
  • Representing the fiduciaries of financial institution in lawsuit alleging breaches of fiduciary duty and prohibited transactions in connection with their in-house plans’ use of affiliated investment vehicles and services
  • Defended or defending the fiduciaries of defined contribution plans sponsored by several major corporations against claims involving employer stock held by those plans
  • Represented US Trust through trial and appeal in its successful defense of breach of fiduciary duty claims stemming from the purchase of privately traded employer stock by an Employee Stock Ownership Plan in Keach v. US Trust


Bar Admissions

  • District of Columbia
  • Illinois

Court Admissions

  • US District Court, Central and Northern Districts of Illinois, District of Colorado, District of Columbia, District of Maryland, and Western District of Wisconsin
  • US Courts of Appeals for the Fourth, Fifth, Seventh, Eighth, Ninth, and Eleventh Circuits


  • Harvard University, J.D., 1997, cum laude
  • Duke University, B.A., 1994, magna cum laude, Phi Beta Kappa

Honors & Awards

  • Recognized by The Best Lawyers in America, Litigation - ERISA, Washington, DC (2023-2024)
  • Ranked by Chambers USA for ERISA Litigation (2022-2024)
  • Recognized by Chambers USA as a leading lawyer for ERISA litigation
  • Recommended by The Legal 500 US for ERISA Litigation (2022-2024)

Professional Activities


  • Honorable John R. Gibson, Eighth Circuit Court of Appeals

Speaking Engagements

  • Speaker, “ERISA Litigation Update” at PLI's Pension Plan Investments 2023: Advanced Perspectives Conference (November 2023)
  • Speaker, “Litigation Update” at PLI's Pension Plan Investments 2021: Advanced Perspectives Conference (November 2021)
  • Panelist, “ERISA Litigation” at PLI’s ERISA 2020: The Evolving World - Part II Conference (December 2020)