Brendan is a trial lawyer who represents companies in complex commercial litigation involving significant financial, operational, and reputational stakes. His practice spans class actions, contract and real estate disputes, employment matters, and antitrust and toxic-tort litigation, with experience across federal and state courts nationwide.
Before co-founding Hayden Ryan & Ciullo, Brendan was a litigation partner at Kirkland & Ellis in Chicago. He represented clients across a wide range of industries, including retail, healthcare, financial services, manufacturing, and consumer products, and handled matters at all stages—from initial pleadings through trial, arbitration, and appeal.
Brendan approaches litigation with an emphasis on trial readiness and strategic clarity. He prepares matters with a focus on the issues most likely to drive outcomes, sharpening arguments early and aligning litigation strategy with his clients’ business objectives, risk tolerance, and long-term interests.
Earlier in his career, Brendan clerked for the Honorable Federico A. Moreno of the United States District Court for the Southern District of Florida, gaining firsthand experience with trial-level decision-making and judicial process.
Brendan also maintains an active pro bono practice, including on behalf of an immigrant seeking asylum, an incarcerated individual seeking early release, and a small-business owner pursuing compensation for services rendered.
experience
Representative Matters
Lead trial counsel for a national sporting goods retailer in a real estate dispute against a mall owner. After obtaining a rare, plaintiff-side partial summary judgment win on tortious interference claims, helped secure a landmark settlement in the middle of a two-week federal jury trial.
Counsel for a Fortune 500 healthcare provider in multiple breach-of-contract disputes arising from the sale of five hospitals in Miami. Prevailed in a net working capital arbitration and two separate injunction proceedings in Delaware and Texas and obtained summary judgment on multiple claims totaling over $50 million.
Defended real estate development firm against class action and personal injury claims alleging offsite property damage and exposure following a demolition project.
Successfully defended a Fortune 50 manufacturing company against Section 1782 petitions seeking U.S. discovery for use in foreign proceedings and prevailed on appeal before the Seventh Circuit Court of Appeals.
Defended chemical manufacturing company in suits alleging personal injury and class claims arising from emissions at a production facility.
Defended healthcare company in class-action lawsuit alleging breach of stock option plan. Successfully moved to strike class allegations, paving the way for consensual resolution.
Represented national credit reporting agency in breach-of-contract dispute with competitor involving data-sharing obligations; matter resolved favorably after discovery.
Represented private equity sponsor in litigation brought by an official committee of unsecured creditors arising from a distressed investment. After a week-long trial, defendants prevailed on all claims, including fraudulent transfer, fiduciary duty, and equitable subordination.
Served as appellate counsel to public-interest organization in effort to vindicate its rights under Illinois’s Freedom of Information Act. On appeal to the Illinois Supreme Court, secured a unanimous decision in client’s favor, while also establishing new precedent governing the retroactive application of state law.
credentials
Kirkland & Ellis LLP
- Partner, 2020–2026
- Litigation Associate, 2016–2020
United States District Court for the Southern District of Florida
- Judicial Law Clerk to the Honorable Federico A. Moreno, 2015–2016
- Litigation Associate, 2014–2015
- Summer Associate, 2013
Education
University of Miami School of Law, J.D., summa cum laude
Order of the Coif; Articles & Comments Editor, University of Miami Law Review
Order of Barristers; Soia Mentschikoff Award for Excellence in Scholarly Writing
- University of Notre Dame, B.A., Political Science & Spanish
- Radio commentator for Notre Dame football and basketball games
Recognition
Best Lawyers: Ones to Watch for Commercial Litigation, 2024–2026
Received a “Litigator of the Week” shout out by The American Lawyer Litigation Daily, September 21, 2018
Representative Matters
Lead trial counsel for a national sporting goods retailer in a real estate dispute against a mall owner. After obtaining a rare, plaintiff-side partial summary judgment win on tortious interference claims, helped secure a landmark settlement in the middle of a two-week federal jury trial.
Counsel for a Fortune 500 healthcare provider in multiple breach-of-contract disputes arising from the sale of five hospitals in Miami. Prevailed in a net working capital arbitration and two separate injunction proceedings in Delaware and Texas and obtained summary judgment on multiple claims totaling over $50 million.
Defended real estate development firm against class action and personal injury claims alleging offsite property damage and exposure following a demolition project.
Successfully defended a Fortune 50 manufacturing company against Section 1782 petitions seeking U.S. discovery for use in foreign proceedings and prevailed on appeal before the Seventh Circuit Court of Appeals.
Defended chemical manufacturing company in suits alleging personal injury and class claims arising from emissions at a production facility.
Defended healthcare company in class-action lawsuit alleging breach of stock option plan. Successfully moved to strike class allegations, paving the way for consensual resolution.
Represented national credit reporting agency in breach-of-contract dispute with competitor involving data-sharing obligations; matter resolved favorably after discovery.
Represented private equity sponsor in litigation brought by an official committee of unsecured creditors arising from a distressed investment. After a week-long trial, defendants prevailed on all claims, including fraudulent transfer, fiduciary duty, and equitable subordination.
Served as appellate counsel to public-interest organization in effort to vindicate its rights under Illinois’s Freedom of Information Act. On appeal to the Illinois Supreme Court, secured a unanimous decision in client’s favor, while also establishing new precedent governing the retroactive application of state law.
Credentials
- Partner, 2020–2026
- Litigation Associate, 2016–2020
United States District Court for the Southern District of Florida
- Judicial Law Clerk to the Honorable Federico A. Moreno, 2015–2016
Hogan Lovells US LLP
- Litigation Associate, 2014–2015
- Summer Associate, 2013
Education
University of Miami School of Law, J.D., summa cum laude
- Articles & Comments Editor, University of Miami Law Review
- Order of the Coif
- Order of Barristers
- Soia Mentschikoff Award for Excellence in Scholarly Writing
University of Notre Dame, B.A., Political Science & Spanish
- Radio commentator for Notre Dame football and basketball games
Recognition
Best Lawyers: Ones to Watch for Commercial Litigation, 2024–2026
Received a “Litigator of the Week” shout out by The American Lawyer Litigation Daily, September 21, 2018
