Brendan R. McGuire is an accomplished trial lawyer, litigator and advisor to companies and individuals. He returned to WilmerHale in 2023 after serving as Chief Counsel to New York City Mayor Eric Adams. Leveraging more than 20 years of experience in private practice and different levels of government, including more than 10 years as a federal prosecutor in the US Attorney’s Office for the Southern District of New York, Mr. McGuire represents clients across a range of industries in complex civil litigation, regulatory compliance, government and internal investigations, and white-collar criminal defense. Clients and peers have praised Mr. McGuire, noting “There’s nobody I’d rather put before a judge or jury,” as well as emphasizing “his sterling character,” “exceedingly excellent reputation,” and “legal acumen.”

In 2021, Mr. McGuire was appointed by Mayor Eric Adams to the newly-created role of Chief Counsel to the Mayor and City Hall. In that position, Mr. McGuire served as the general counsel of the administration as well as the Mayor’s legal and strategic counselor. In addition, he had operational, policy and budgetary oversight of 10 city agencies, partnered with deputy mayors and significant agency heads on key administration priorities, and worked closely with the federal and state governments on behalf of the city.

Prior to serving as Chief Counsel, Mr. McGuire was a partner in WilmerHale’s White Collar Defense and Investigations Practice. His practice included representing officers, directors and corporations in grand jury and regulatory investigations, including those conducted by the DOJ, SEC, CFTC, IRS and state law enforcement agencies. He represented clients on matters concerning alleged securities fraud, accounting fraud, tax offenses, bribery, embezzlement, money laundering and FCPA violations. Mr. McGuire also advised in the areas of national security, cybersecurity and privacy, and export controls and economic sanctions.

Before joining WilmerHale in 2016, Mr. McGuire served for more than ten years as an Assistant US Attorney in the US Attorney’s Office for the Southern District of New York. During his tenure as Assistant US Attorney, Mr. McGuire was appointed to lead the Public Corruption Unit and then the Terrorism and International Narcotics Unit. As chief of the Public Corruption Unit, Mr. McGuire led some of the most notable investigations and prosecutions of New York officials in recent years, as well as cases involving violations of securities fraud, the federal fraud and bribery statutes, healthcare fraud and tax evasion. He also oversaw multiple corporate prosecutions, including the settlement of the largest municipal fraud case in history. During his tenure as chief of the Terrorism and International Narcotics Unit, Mr. McGuire supervised investigations and prosecutions of international and domestic terrorism, money laundering, violations of economic sanctions and export control laws, espionage, and global narcotics trafficking. In that position, he regularly coordinated criminal investigations with the intelligence community, the Department of the Treasury, the Department of Defense, the Department of State and foreign governments. Prior to his supervisory positions as a member of the Terrorism Unit, Mr. McGuire handled some of the most significant terrorism cases within the Department of Justice, including the 2009 kidnapping of Captain Richard Phillips by Somali pirates in the Indian Ocean, the 2010 prosecution of Faisal Shahzad for the attempted bombing of Times Square and the 2011 prosecution of Russian arms dealer Viktor Bout for conspiring to kill Americans.

After receiving his law degree, Mr. McGuire practiced as a litigator at two prominent New York law firms where he specialized in white-collar defense and corporate investigations. He also clerked for the Honorable Peter K. Leisure of the US District Court for the Southern District of New York.


    • Represented US financial services firms in parallel investigations by the DOJ and the SEC regarding employee theft and misconduct
    • Represented elected New York State official in parallel federal and state investigations of public corruption and tax fraud
    • Represented US trading firm in connection with DOJ investigation of theft of trade secrets and cyber intrusion
    • Represented former employee of Fortune 500 company in connection with DOJ fraud and money laundering investigation and related civil litigation
    • Advised global financial services firm regarding misconduct by senior employee
    • Represented employees of international airline in DOJ investigation of illegal smuggling
  • Pro Bono Matters

    • Represented indigent criminal defendant charged with fraud by DOJ
    • Represented nonprofit athletic commission in DOJ corruption investigation


  • Named to Lawdragon’s 2024 List of 500 Leading Global Cyber Lawyers.
  • City & State New York’s 2023 Law Power 100 list
  • Best Lawyers in America, Criminal Defense: White Collar (2021–2022)
  • Chambers USA: World's Leading Lawyers for Business, Litigation: White-Collar Crime & Government Investigations (New York) (2020–2021)
  • Henry L. Stimson Medal for outstanding career performance as an Assistant US Attorney (2015)
  • Federal Law Enforcement Foundation Prosecutor of the Year (2013)
  • National Committee on American Foreign Policy 21st Century Leader Award (2012)
  • Anti-Defamation League Shield Award (2012)
  • Attorney General's Award (2011)

Insights & News


  • Education

    • JD, New York University School of Law, 2002

    • BA, Williams College, 1998

  • Admissions

    • New York

  • Clerkships

    • The Hon. Peter K. Leisure, US District Court for the Southern District of New York



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