Gregory Lantier

GREG LANTIER is a trial lawyer and appellate advocate who represents companies in their most consequential disputes. His practice focuses on complex patent, copyright, and trade secret matters that sit at the intersection of law, technology, and business strategy.

Greg has extensive experience advocating for clients across the full litigation lifecycle, including jury trials, post-grant proceedings, and appellate review. He regularly appears before state and federal trial and appellate courts, the U.S. Supreme Court, the U.S. International Trade Commission, the U.S. Court of Federal Claims, and before the Patent Trial and Appeal Board (PTAB). 

Clients turn to Greg in matters that demand both courtroom judgment and strategic perspective. He has led large, multidisciplinary trial teams in disputes carrying significant commercial exposure, while also efficiently handling targeted matters with lean teams when speed and cost control are paramount. Greg’s industry experience spans software and technology, financial services, medical devices, telecommunications, semiconductors, biotechnology, pharmaceuticals, and defense.

In addition to his litigation work, Greg advises clients on intellectual property risk management, licensing disputes, and policy-driven developments affecting IP rights. He has also worked closely with foreign counsel in cross-border disputes involving parallel trial and appellate proceedings outside the United States.

His work has been widely recognized by leading legal publications and industry guides. Greg is recognized by Chambers USA in the District of Columbia for Intellectual Property: Litigation (2025). Benchmark Litigation named Greg a “National Practice Area Star” in 2026, 2020–2024, and 2017 for his work in intellectual property, and he was honored as “Litigator of the Week” by Litigation Daily following the jury verdict on behalf of a technology client in May 2023. Additionally, Managing IP selected Greg as an “IP Star” in 2022–2025, and he was recognized with a “2019 Impact Case of the Year Award” for his work in the U.S. Supreme Court case PNC Bank National Association v. Secure Axcess. Greg was also listed in the 2020–2024 editions of Super Lawyers in Washington, D.C.

U.S. Supreme Court

• Represented petitioner in PNC Bank v. Secure Axcess, 138 S.Ct. 1982 (2018) (vacating court of appeals).
• Represented respondent in Bowman v. Monsanto, 133 S.Ct. 1761 (2013) (affirming court of appeals).
• Represented respondent in Stanford v. Roche, 563 US__, 131 S.Ct. 2188 (affirming court of appeals).

U.S. Court of Appeals for the Federal Circuit

• Successfully argued for affirmance of Patent Trial and Appeal Board’s findings of invalidity and obtained reversal of PTAB’s findings of no invalidity in order to obtain complete victory in appeals from three IPR decisions for financial institutions client.
• Successfully argued for reversal of Patent Trial and Appeal Board’s final written decision of no invalidity for semiconductor manufacturer client.
• Successfully argued appeal on behalf of a software company client to obtain affirmance of ruling that asserted patent was invalid.
• Successfully argued two appeals on behalf of insurance company clients in patent infringement actions brought by Intellectual Ventures. Between the two appeals, the Federal Circuit affirmed the district court’s findings that three Intellectual Ventures’ patents are invalid under 35 U.S.C. § 101, and that Intellectual Ventures did not own a fourth patent.
• Successfully argued for affirmance of district court’s order dismissing 243 claims as reciting ineligible subject matter under 35 U.S.C. § 101.

U.S. District Courts

• Led trial team in obtaining jury verdict of no infringement and invalidity with respect to four asserted software patents in the U.S. District Court for the Western District of Texas. Named “Litigator of the Week” by Litigation Daily, following verdict in May 2023.
• Tried two high-profile cases within six months for financial services client in the U.S. District Court for the Eastern District of Texas.
• Represented client in obtaining jury verdict of no liability with respect to two asserted patents in the U.S. District Court for the Western District of Texas.
• Obtained dismissal of patent infringement action filed against software client in the U.S. District Court for the District of Delaware.
• Obtained dismissal of a seven-patent infringement complaint because all claimed patent-ineligible subject matter under 35 U.S.C. § 101 in the U.S. District Court for the Central District of California. Successfully argued for dismissal of patent infringement complaints filed by Intellectual Ventures, on behalf of insurance company clients in the U.S. District Court for the Western District of Pennsylvania.
• Represented medical device manufacturer asserting infringement of patents relating to methods and devices for performing spinal surgery in the U.S. District Court for the Eastern District of Pennsylvania. The jury found the asserted patents infringed and not invalid.
• Represented financial institution sued for infringement of patents relating to data compression and decompression in the U.S. District Court for the Southern District of New York. The court granted motions for summary judgment of invalidity and no infringement.

U.S. Court of Federal Claims

• Successfully obtained summary judgment of no patent infringement on behalf of supplier of mail sorting machines to the United States Postal Service.

State Courts

• Represented biotechnology client in patent ownership and trade secrets dispute, resulting in favorable judgment after a bench trial in the Delaware Court of Chancery.
• Represented major computer technology client in license dispute with a graphics technology company in the Delaware Court of Chancery, resulting in settlement.

U.S. International Trade Commission

• Member of trial team representing complainant, a garage door manufacture, in a Section 337 investigation against competitor. Exclusion order issued (ITC Inv. No. 337-TA-1118).
• Member of trial team representing respondent, a leading technology company, in a Section 337 investigation. Initial Determination of no violation issued with respect to two of three asserted patents (ITC Inv. No. 337-TA-1093).
• Member of trial team representing respondent, a leading technology company, in a Section 337 investigation. Initial Determination of no violation was issued (ITC Inv. No. 337-TA-794).
• Represented flash memory manufacturer accused of infringing patents in two successive Section 337 investigations at trial before the International Trade Commission. The ITC made a Final Determination of no violation in both investigations (ITC Inv. Nos. 337-TA-526, 337-TA-560).

Patent Trial and Appeal Board

• Argued successfully for invalidation of four remote check deposit patents on behalf of financial services client.
• Appearing pro hac vice, argued successfully on behalf of semiconductor manufacturer client to invalidate all challenged claims of patent relating to computer memory.
• Appearing pro hac vice, successfully presented oral argument in trial of covered business method review proceeding on behalf of two large financial services firms.

Arbitration

• Served as lead trial counsel in successful arbitration hearing to enforce patent license agreement.

The above matters were handled prior to joining Sidley.

• Member, American Bar Association
• Member, Virginia State Bar Association
• Member, New York State Bar Association
• Member, Federal Circuit Bar Association