

Overview
Mr. Grimsley is a first-chair trial lawyer with more than 30 years of experience handling complex litigation in courts throughout the country. His practice includes intellectual property, antitrust, class action, and commercial disputes, with experience managing matters through trial and appeal.
His intellectual property practice spans trademark, trade dress, copyright, patent, and trade secret disputes across industries, including consumer products, aerospace, military hardware, medical equipment, and industrial equipment. Mr. Grimsley also represents clients in antitrust litigation, government investigations, and business disputes involving breach of contract, tortious interference, fiduciary duties, RICO, and other claims.
Mr. Grimsley is recognized in both the WTR 1000 and the IAM/WTR Copyright 1000. Mr. Grimsley is also the author of the Annotated Manual for Complex Litigation, Fourth.
Experience
- Obtained multi-million dollar judgment for consumer products company against foreign manufacturer and domestic distributor for trade dress infringement
- Obtained judgment for smoking products company invalidating trademark applications of cannabis company in precedential decision, affirmed on appeal, establishing district court’s jurisdiction to address pending applications
- Hired as lead trial counsel 30 days before trial in a Lanham Act dispute involving a medical device company, securing dismissal of certain claims, a settlement payment from one adverse party, and a jury verdict in the client’s favor on the remaining claims and counterclaims
- Defended an aerospace company in federal trade secret litigation involving patented LIDAR sensor technology, obtaining dismissal of all claims challenging the client’s ownership of the technology
- Hired as lead counsel 90 days before trial for a Hong Kong-based trading company and Chinese factories, implementing a discovery strategy that resulted in a $12 million summary judgment ruling
- Successfully defended the country’s largest self-move truck rental organization in a multidistrict antitrust class action alleging illegal price fixing
- Represented a leading guitar manufacturer in an FTC price-fixing investigation, which closed without charges or a consent decree, and subsequently obtained dismissal of related multidistrict antitrust class litigation
- Obtained dismissal of a RICO and securities fraud class action against a developer, with the dismissal affirmed in a precedent-setting Third Circuit decision
Focus Areas
Related News & Insights
Publications & Presentations
- Author, “Annotated Manual for Complex Litigation, 4th Edition,” Thomson Reuters, May 2025
- “The Company Deposition—The Critical Role of In-House Counsel,” Association of Corporate Counsel, Arizona Chapter Newsletter, 2nd Quarter 2018
- “Arizona LLCs—Forget What You think You Know About Duties,” Association of Corporate Counsel, Arizona Chapter, February 2017
- “Drafting Enforceable Class Action Waivers,” CLE Webcast (Celesq Ed/West Legal Ed), November 2016
Credentials
- Order of the Coif
- summa cum laude
- United States Court of Appeals, Federal Circuit
- United States Court of Appeals, Fifth Circuit
- United States Court of Appeals, Ninth Circuit
- United States Court of Appeals, Eleventh Circuit
- United States District Court, District of Arizona
- United States District Court, Northern District of Illinois
- United States District Court, Southern District of New York
- United States District Court, Western District of Wisconsin
- American Bar Association
- Arizona Bar Association
- Maricopa County Bar Association
- Chairman, Board of Directors, Rocky Mountain School for the Gifted and Creative, Boulder, CO (2009-2011)
- International Arbitration “Attorney of the Year,” Corporate INTL, 2015
- Arizona Business Magazine
- “AB Top Lawyers,” Alternative Dispute Resolution, 2011
- WTR 1000
- Recommended, Copyright Practice, Arizona, 2026
- Recommended, Arizona, 2025-2026


