Barbara Borden


I am passionate about helping clients execute on their strategic objectives and love negotiating deals.

Barbara is co-chair of Cooley’s mergers & acquisitions practice. She focuses on public and private M&A, cross-border transactions, joint ventures and other complex transactions. Barbara represents strategic and financial buyers and sellers in public and private acquisitions, and has significant experience counseling boards of directors in connection with M&A and related governance, as well as anti-takeover matters.

Download full bio 


  • Horizon Therapeutics to Acquire Viela Bio 

  • Bristol Myers Squibb to Acquire Turning Point Therapeutics for $4.1 Billion 

  • Vividion Therapeutics Agrees to Sell to Bayer for up to $2 Billion 

  • Horizon Therapeutics to Be Acquired by Amgen for Approximately $28 Billion 

  • VelosBio Agrees to Sell to Merck for $2.75 Billion 

  • View all


  • Arizona State University – Sandra Day O'Connor College of Law
    JD, magna cum laude, Order of the Coif, 1984

  • University of Virginia
    BA, Government,
    with high distinction, 1981

Admissions & Credentials



  • American Bar Association

  • San Diego County Bar Association

Rankings & Accolades

    San Diego Business Journal’s SD 500 list (2022)

    Best Lawyers in America: Lawyer of the Year (2018, 2021)

    Daily Journal: Top Women Lawyers (2017)

    Legal 500 US: Hall of Fame in M&A/corporate and commercial – M&A (2020 – 2021); Key Lawyer, Healthcare: Life Sciences

    The Recorder: Trusted Advisor for Life Sciences (2016)

    Daily Journal: Top 100 Lawyers in California (2014-2017)

    The Recorder: Women Leaders in Tech Law (2015-2018)

    San Diego M&A Advisor of the Year: Buy-Side Transaction (2015)

    The Best Lawyers in America: Lawyer of the Year, San Diego Securities and Capital markets (2014)

    Legal 500 US: Mergers, Acquisitions and Buyouts for Large Deals (2011-2018)

    The Best Lawyers in America: Corporate Governance and Compliance Law, Corporate Law, M&A, Securities Regulation and Securities/Capital Markets Law (2010-2021)

    Super Lawyers: Mergers and Acquisitions (2007-2022)