People / Daniel Geyser
Dan Geyser

Daniel L. Geyser

Partner | Chair - U.S. Supreme Court Practice

* Admitted only to practice in Texas and California. Not admitted in Colorado.

Daniel L. Geyser is Chair of the firm’s U.S. Supreme Court Practice and a member of its Appellate Group. He focuses on complex and high-stakes appellate litigation, representing clients in the Supreme Court of the United States and in courts of appeals nationwide. He was named one of Law360’s 2022 “Appellate MVPs,” an honor awarded to only four lawyers in the United States—Dan’s second time winning the award in the past four years.

Dan is widely regarded as one of the nation’s leading Supreme Court and appellate lawyers. The Legal 500 reports that Dan is “recognized by peers and clients alike as ‘an extraordinary oral advocate and brief writer,’” “stand[ing] out for his sheer brainpower and creative thinking” (2020); clients say “Geyser’s intellect and analysis are peerless” (2021); “‘[h]is legal analysis is brilliant and on point, and his written and oral advocacy is very strong and powerful’” (2020). Chambers USA describes Dan as a “‘superb lawyer with impeccable judgment and a wonderful manner in oral arguments,’” adding he has “‘that rare ability to make clients and legal counsel at ease, even under difficult circumstances. He instills confidence’” (2020).

Dan is among a select group of elite lawyers who regularly handle significant disputes in the U.S. Supreme Court. Listed among the “veritable who’s who of the Supreme Court bar” (Empirical SCOTUS, 2018), Dan has argued sixteen Supreme Court cases in private practice, with a seventeenth argument coming later this Term. He has twice had three cert. petitions granted in a 12-month period (a feat matched by few global firms), and personally handled over 5% of the Court’s merits docket in OT 2018. He has been named to the National Law Journal’s “Appellate Hot List” (2018, 2022), earned weekly honors as a Law360 “Legal Lion” (2018), achieved national appellate rankings in Chambers USA and The Legal 500 (2019-2023), and was named OT 2017’s “top performing” brief-writer among the Court’s repeat players (based on a 2018 empirical study using brief-analyzing software). His petitions are regularly featured among the “Petitions of the Week” on SCOTUSblog, and he is a three-time winner of NAAG’s Best Brief Award for excellence in brief-writing before the Court (2008-2009, 2011). In the past half-decade, Dan ranks among the top five lawyers nationwide for total Supreme Court arguments in private practice, notching “rare victor[ies]” (SCOTUSblog, 2021) and “huge win[s]” (Reuters, 2019) in cases that industry experts said could not be won.

Dan routinely matches up against the top litigators in the country. He has convinced the Supreme Court to grant review over the opposition of elite appellate groups at multiple Am Law 20 firms, and his recent wins have come against superstars at Am Law 10 firms and the Solicitor General’s Office. In the past two Terms alone, Dan has secured multiple wins in major business disputes—including striking down an Act of Congress under the Bankruptcy Clause, winning a closely watched battle for taxpayers under the Bank Secrecy Act, reshaping post-arbitration rules nationwide under the Federal Arbitration Act, and arguing a multibillion-dollar dispute under the False Claims Act, one of Dan’s three cert. grants in 2022.

Beyond the Supreme Court, Dan handles high-stakes matters in appellate courts nationwide, litigating cases in virtually every major area of federal law (especially securities, bankruptcy, patents, ERISA, and arbitration). For plaintiffs, he has crafted legal strategy in matters generating over a half-billion in recovery. For defendants, he has won appeals in 8- and 9-figure disputes. He has special expertise at the rehearing stage, and has argued before the en banc Ninth Circuit (winning 10-1). In addition to an active federal practice, Dan has handled landmark state-court appeals, including arguing seven times before the Texas Supreme Court.

Before joining Haynes Boone, Dan ran his own award-winning appellate practice; served as the appellate chair of a prominent litigation boutique (also leading that firm to the National Law Journal’s “Appellate Hot List” and a Chambers USA national-appellate ranking); and was an appellate partner in one of the nation’s top litigation firms, building its appellate practice while focusing especially on complex patent appeals and bankruptcy cases.

From 2007 to 2011, Dan served in the Office of the Solicitor General of Texas, where he conducted and supervised appellate litigation for the State. In addition to handling his own docket, his experience in the office included advising other divisions on appellate and trial strategy, revising countless briefs in cases across all subject areas, and extensively preparing other attorneys (in moot courts and otherwise) for oral argument. In his last week on the job, Dan argued before the Texas Supreme Court in Severance v. Patterson, one of the State’s most important cases in recent memory—a constitutional attack on the public’s historic access to open beaches; he had earlier won “a rare motion to rehear the case” (Austin American-Statesman, 2011). The same week, Dan also won a major case in the U.S. Supreme Court, Sossamon v. Texas, involving Congress’s spending power and state sovereignty; Dan wrote the State’s briefs in that case and crafted its core legal theories and appellate strategy. He was also the principal writer of the State’s invitation brief in Rhine v. Deaton, a case marking the very first time the U.S. Supreme Court called for a state solicitor general to file a brief expressing the views of a State.

Dan graduated Phi Beta Kappa, with honors and distinction, from Stanford University, and with honors from Harvard Law School, where he was the Notes Chair of the Harvard Law Review, a best-brief winner and oralist on the championship team of Harvard’s moot-court competition, and a research assistant to Professor Laurence H. Tribe, working on his academic writing and appellate docket. After law school, Dan clerked for the Hon. Alex Kozinski of the U.S. Court of Appeals for the Ninth Circuit. He has received the State Bar of California’s Wiley W. Manuel Award for Pro Bono Legal Services and is a past appointee to the U.S. Court of Appeals for the Second Circuit Pro Bono Panel.

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  • Recognized in Chambers USA, Chambers and Partners, in Appellate Law – USA – Nationwide, 2019-2023; in Appellate - Texas 2022-2023
  • Ranked in The Legal 500, Legalease Ltd., in Appellate, 2019-2022
  • Twice named a Law360 “Appellate MVP,” Portfolio Media, 2019, 2022
  • Recognized by Law360, Portfolio Media, as a “Legal Lion,” May 31, 2018
  • National Law Journal’s “Appellate Hot List,” 2018, 2022
  • Recognized by Texas Super Lawyers, Thomson Reuters, in Appellate Law, 2019-2023
  • Recognized by D Magazine, D Magazine Partners, Best Lawyers in Dallas, Appellate Law, 2020
  • National Association of Attorneys General’s “Best Brief Award,” 2008-2009, 2011
  • State Bar of California’s Wiley W. Manuel Award for Pro Bono Legal Services, 2006
  • "SCOTUS Spotlight: Daniel Geyser” (SCOTUSblog’s SCOTUStalk, 2023)
  • High Court Veteran Examines Changing Oral Arguments” (Bloomberg Law’s “Cases and Controversies” Podcast, 2023)
  • “The Fine Art of Rebuttal” (Appellate Judges Education Institute, 2023 Summit)
  • “Supreme Court Panel” (5th Circuit Bar Association’s Appellate Advocacy Seminar, 2023)
  • “Navigating FCA Appeals” (Federal Bar Association’s Qui Tam Conference, 2023)
  • “Supreme Court Panel” (5th Circuit Bar Association’s Appellate Advocacy Seminar, 2022)
  • “U.S. Supreme Court Update” (UT Law CLE’s Conference on State and Federal Appeals, 2022)
  • “A Supreme Court Review: The 2020 Term” (Dallas Democratic Forum, 2021)
  • “2021 Supreme Court Round Up” (The Federalist Society’s Houston Lawyers Chapter, 2021)
  • “SLLC Supreme Court Midterm Webinar” (State and Local Legal Center, 2021)
  • “Learning From Appeals” (TexasBarCLE’s Advanced Intellectual Property Litigation, 2020)
  • “Supreme Court Review” (Dallas Bar Association, 2020)
  • “SCOTUS Review with The Lawbook” (The Texas Lawbook, 2020)
  • “Getting Cert. Granted: The Art and Science of Obtaining SCOTUS Review” (UT Law CLE’s Conference on State and Federal Appeals, 2019)
  • “U.S. Supreme Court Update” (Texas State Bar College’s State Bar Summer School, 2012, 2015-2017)
  • “Writing Persuasive Facts and Framing the Questions Presented” (State Bar of Texas’s Legal Writing to Win, 2015)
  • “Approaching the Legal Writing Project: Understanding the Objective of Every Document” (TexasBarCLE’s Exceptional Legal Writing, 2013)
  • “The Roberts Court at Five Years” (Texas State Bar College’s State Bar Summer School, 2011)


J.D., Harvard Law School, 2002

B.A., Stanford University, 1999


Law clerk, Honorable Alex Kozinski, U.S. Court of Appeals for the Ninth Circuit, 2002-2003




Court Admissions

United States Supreme Court

U.S. Court of Appeals for the First Circuit

U.S. Court of Appeals for the Second Circuit

U.S. Court of Appeals for the Third Circuit

U.S. Court of Appeals for the Fourth Circuit

U.S. Court of Appeals for the Fifth Circuit

U.S. Court of Appeals for the Sixth Circuit

U.S. Court of Appeals for the Seventh Circuit

U.S. Court of Appeals for the Eighth Circuit

U.S. Court of Appeals for the Ninth Circuit

U.S. Court of Appeals for the Eleventh Circuit

U.S. Court of Appeals for the District of Columbia Circuit

U.S. Court of Appeals for the Federal Circuit

U.S. District Court for the Central District of California

U.S. District Court for the District of Colorado

U.S. District Court for the Eastern District of Texas

U.S. District Court for the Northern District of Texas

Press Release
Dan Geyser Argues Major Bankruptcy Case Before the U.S. Supreme Court, Receives National News Covera [...]
January 11, 2024

Haynes Boone U.S. Supreme Court Practice Chair Daniel Geyser argued before the Supreme Court on Jan. 9, in U.S. Trustee v. John Q. Hammons Fall 2006, a significant dispute over $326 million in bankruptcy fees.   Geyser’s argument and the case received national coverage from news outlets covering both the Supreme Court and bankruptcies. The case involved the aftermath of the Supreme Court’s earlier [...]