ANGELA ZAMBRANO co-leads Sidley’s Dallas office and is a premier commercial litigator, having recently been named The American Lawyer’s “Litigator of the Week” based on her complete victory in a US$100 million earn out arbitration proceeding, shortlisted as the “Litigator of the Year” by IFLR’s Women in Business Law, and recognized in “Commercial Litigation” by Best Lawyers in America from 2016–2022. Based on her outstanding trial results and sage legal advice in the Boardroom, she is ranked by Chambers USA in Texas: Dallas, Fort Worth & Surrounds – Commercial Litigation from 2020–2023, one of only a few women so recognized in the state of Texas.

Angela co-leads the firm’s Commercial Litigation and Disputes group and leads the firm’s Dallas litigation group. The firm’s Dallas litigation group has received considerable recognition, including being ranked by Chambers USA and previously named “Litigation Department of the Year” by Texas Lawyer.

Angela has won many high profile cases in a wide variety of areas within commercial litigation, including partnership disputes, purchase price adjustments, indemnification disputes, and earn out arbitrations, fraud and breach of contract disputes, energy litigation, securities litigation, consumer class action litigation, class and collective action employment litigation, trade secret disputes, 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 is also active in firm leadership and in the Dallas community. She serves as a member of Sidley’s Executive Committee and as a co-leader of Sidley’s women’s initiative. Angela previously served as the President of the Dallas Women Lawyer’s Association. She currently serves on the Executive Board of the Dedman School of Law, having previously served as an adjunct professor teaching pretrial procedure. D Magazine named Angela to its “Best Lawyers in Dallas” list (2023; 2016–2020), Benchmark Litigation has named her a “Litigation Star” in Texas for her work in Commercial Litigation and Insurance (2015–2024), and she was shortlisted for “Commercial Arbitration Lawyer of the Year” by Women in Business Law America (2023). She has received the Outstanding Female Lawyer and Outstanding Board Member awards by the Dallas Women Lawyer’s Association, the Distinguished Alumni Award by SMU Women in Law, and named the 2016 Emerging Leader by the SMU Dedman School of Law.

Recent Experience

• Currently representing an energy services company in which she successfully moved to dismiss all of an intervenor’s claims against her client;

• Currently representing a publicly traded company in an action against the Federal Trade Commission (FTC) in which she successfully obtained dismissal with prejudice of the FTC’s two primary courts against her client;

• Currently representing a publicly traded company in an alleged whistleblower claim in which she successfully transferred the case to the Northern District of Texas and compelled arbitration;

• Currently representing a client in a False Claims Act matter in which she successfully moved to enjoin a former private equity partner from disclosing confidential information;

• Successfully represented a chemical manufacturing company in trade secret litigation, including successfully obtaining preliminary injunctive relief and a temporary restraining order;

• Represented a 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;

• Represented an 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;

• Represented a publicly traded building products company in a US$100 million earn-out proceeding in which Sidley prevailed on all claims;

• Represented a 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;

• 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;

• Successfully represented a 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 an energy company in an arbitration relating to indemnification claims;

• Represented a client relating to multiple inquiries from DOJ, USDA and TDA relating to government contracts issues;

• Represented a mortgage company in a class action relating to the purchase of assets from the government that she successfully resolved;

• Represented a mortgage company in multiple misappropriation of trade secrets and employee-related disputes, including successfully compelling dispute to arbitration;

• Successfully represented an energy company, healthcare companies, and a telecommunications company in multiple FLSA and wage payment matters;

• Represented a 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 a 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 an entertainment company in connection with class action consumer disputes related to the company’s rewards program and gift cards;

• Represented an energy company in a trespass dispute in which she successfully defeated a plea to the jurisdiction and motion for protection; and

• Advised on multiple data breach and privacy-related investigations and related litigation