Angela C. Zambrano

ANGELA ZAMBRANO is a member of Sidley’s Executive Committee, is a co-leader of Sidley’s Dallas office, and is a co-leader of the firm’s 700+ member Litigation global practice group. Based on her outstanding trial results and sage legal advice in the boardroom, she is ranked Band 1 by Chambers USA in Litigation: General Commercial in Texas: Dallas, Fort Worth & Surrounds (2020–2025), one of only a few women so recognized in the state of Texas.

“Angela is relentless. Where some say it’s impossible or too difficult, she takes it with her and works incredibly hard. Her work product is exceptional and is so well researched.”
Chambers USA 2024

Angela’s first chair trial practice spans across many different substantive areas of litigation. According to Chambers USA, clients hire her because “she sees the big picture and is exceptional in the courtroom.” Angela serves as lead counsel in a wide variety of litigation: fraud and breach of contract disputes, energy litigation, securities litigation, consumer class action litigation, class and collective action employment litigation, trade secret disputes, False Claims Act matters, partnership disputes, purchase price adjustments, indemnification disputes, earn-out arbitrations, litigation against governmental entities, whistleblower-related litigation, data breach and privacy related investigations and litigation, commercial vendor disputes and litigation, and telecommunications litigation. She also has an active board of directors–level internal investigations practice, particularly with respect to accounting, privacy, whistleblower, and employment related matters. Her arbitration experience has earned her a spot on the American Arbitration Association’s Roster of Arbitrators.

Angela was previously named The American Lawyer’s “Litigator of the Week” based on a complete victory in a US$100 million earn-out arbitration proceeding. In 2023, she was named “Commercial Arbitration Lawyer of the Year” and was shortlisted in 2022 as the “Litigator of the Year” by IFLR’s Women in Business Law Americas Awards. Angela also was recognized in “Commercial Litigation” by Best Lawyers in America from 2016–2023. Angela was recognized as a “Client Service All-Star” by BTI Consulting Group in 2023, the only legal industry ranking and attorney recognition based solely on organic client input.

Angela serves on the Executive Board of the Dedman School of Law and as an adjunct professor at the law school. Angela previously served as the president of the Dallas Women Lawyer’s Association. D Magazine named Angela to its “Best Lawyers in Dallas” list (2025; 2023; 2016–2020), and Benchmark Litigation has named her a “Litigation Star” in Texas for her work in Commercial Litigation and Insurance (2015–2024). She has received the “Outstanding Female Lawyer” (2019) and “Outstanding Board Member” awards by the Dallas Women Lawyers Association (2017), the “Distinguished Alumni Award” by SMU Women in Law (2017), and named the 2016 “Emerging Leader” by the SMU Dedman School of Law.

• Currently representing manufacturing company against alleged whistleblower in Sarbanes-Oxley claim in the Northern District of Texas; successfully moved to dismiss majority of named defendants (affirmed by the 5th Circuit) and compelled arbitration of all remaining claims (summary judgment obtained in arbitration).
• Currently representing financial services company in putative class action litigation filed in the Eastern District of Texas by account holder against multiple major financial institutions alleging fraud, RICO, and breach of contract; successfully compelled all claims to arbitration.
• Currently representing financial services company in Texas state court against contract counterparty in breach of contract claim valued at more than US$50 million.
• Currently representing financial services company in multiple arbitration proceedings before FINRA against former leaders alleging improper termination of contract after leader misconduct.
• Currently representing CFO of energy company in securities litigation pending in the Southern District of Texas.
• Currently representing The Big 12 Conference, Inc. in multiple antitrust class action matters in the Northern District of California, the District of Colorado, and the Second Circuit related to compensation issues.
• Represented client in multiple False Claims Act matters in which Sidley successfully moved for summary judgment on all counts against Relator in the Eastern District of Texas.
• Represented energy services company in dispute relating to the interpretation of an LLC agreement which Sidley successfully prevailed on all counts (including recovering damages) in Delaware Chancery Court (affirmed by the Delaware Supreme Court).
• Represented a publicly traded social media company in an action against the Federal Trade Commission (FTC) in the Northern District of Texas which Sidley successfully obtained dismissal with prejudice of the FTC’s two primary claims against client and settled the remaining claims.
• Represented a publicly traded company in a putative class action alleging discrimination under Title VII in which Sidley successfully moved to dismiss complaint in the Eastern District of Texas.
• Successfully represented financial services company in litigation against the Consumer Financial Protection Bureau.
• Obtained summary judgment on behalf of a telecommunications company in the Eastern District of Pennsylvania (affirmed on appeal).
• Successfully represented financial services company in Consumer Financial Protection Bureau inquiry.
• Successfully represented chemical manufacturing company in trade secret litigation, including successfully obtaining preliminary injunctive relief and a temporary restraining order.
• Successfully represented REIT as lead trial counsel in a final evidentiary hearing of an earn-out arbitration and obtained a complete victory for her client, including a multimillion-dollar counterclaim award.
• Successfully represented energy company in a state court matter as lead counsel and successfully obtained a summary judgment of all claims against her client within six months of the case being filed.
• Successfully represented a publicly traded building products company in a US$100 million earn-out proceeding in which Sidley prevailed on all claims.
• Successfully represented private equity client in the arbitration of an earn-out dispute relating to a healthcare company in which she obtained a complete victory for her client.
• Successfully represented a publicly traded company in a California class action litigation related to consumer location services in which Sidley successfully moved to dismiss and compel arbitration of all claims (plaintiff abandoned claims and did not seek arbitration).
• Successfully defeated a preliminary injunction filed against a telecommunications company for failure to provide services during the pandemic.
• Represented a publicly traded building products company in a group of securities class actions and derivative actions in which she successfully moved to transfer and dismiss derivative claims and favorably resolved securities claim.
• Successfully represented telecommunications company in a damages trial in which Sidley’s damages model was adopted by the Court.
• Represented a retail client in multiple wage-and-hour collective actions in which Sidley successfully won motions to transfer and compel arbitration.
• Successfully moved to compel arbitration of all claims by a vendor against her energy company client.
• Represented energy company in an arbitration relating to indemnification claims.
• Represented client relating to multiple inquiries from DOJ, USDA, and TDA relating to government contracts issues.
• Represented mortgage company in a class action relating to the purchase of assets from the government that she successfully resolved.
• Represented mortgage company in multiple misappropriation of trade secrets and employee-related disputes, including successfully compelling dispute to arbitration.
• Successfully represented energy company, healthcare companies, and a telecommunications company in multiple FLSA and wage payment matters.
• Represented private equity client in an arbitration where she obtained several early favorable rulings and ultimately a favorable settlement in which the client was able to recoup its entire investment in a media company.
• Represented several insurance-related entities in an action involving allegations of fraud and breach of contract in which she obtained a dismissal with prejudice for all of her clients.
• Represented pharmaceutical company in an arbitration with its vendor in which she obtained interim measures from the arbitrator shortly after the arbitrator was appointed, leading to a favorable settlement for her client.
• Successfully represented entertainment company in connection with class action consumer disputes related to the company’s rewards program and gift cards.
• Represented energy company in a trespass dispute in which she successfully defeated a plea to the jurisdiction and motion for protection.
• Advised on multiple data breach and privacy-related investigations and related litigation.

• Master, The Patrick E. Higginbotham Inn of Court
• Executive Board Member, SMU Dedman School of Law
• Trustee, Dallas Theatre Center
• Board Member, Dallas Women Lawyers Foundation
• Dallas Bar Association, Trial Skills Committee Member
• Advisory Board Member and Former President, Dallas Women Lawyers Association
• American Arbitration Association, Roster of Arbitrators
• Northwestern University Kellogg School of Management, Executive Leadership Program Certification, 2025
• Former Board Member, Texas Appleseed
• Leadership Dallas (2019 Class)
• Litigation Counsel of America, The Trial Lawyer Honorary Society
• American Bar Association
• Texas Bar Association
• New York Bar Association