About
James R. “Sonny” Chastain, Jr. is a distinguished partner at Kean Miller LLP in Baton Rouge, Louisiana, specializing in business litigation and intellectual property law. With a career of over three decades, Sonny has earned recognition for his exceptional legal acumen and dedication to his clients.
Sonny holds a Bachelor of Science in Finance from Louisiana State University and a J.D. from the LSU Law Center. After graduation, he served as a law clerk to Hon. Frank J. Polozola of the United States District Court for the Middle District of Louisiana, gaining invaluable insight into the judicial process.
Since joining Kean Miller in 2000, Sonny has represented clients in diverse matters, including contract disputes, intellectual property infringement, unfair trade practices, and antitrust issues. His expertise includes copyright and trademark registration, brand management, and arbitration agreements. Sonny also provides mediation services for disputes involving property damage, insurance coverage, and personal injury.
Sonny’s extensive litigation experience includes defending major financial institutions in arbitration agreements, representing designers in copyright disputes, and assisting manufacturers in defending allegations of trade secret misappropriation. He has also successfully prosecuted numerous trademark applications and represented clients in opposition proceedings before the U.S. Patent and Trademark Office and the Trademark Trial and Appeal Board.
Highly regarded in his field, Sonny has been recognized in The Best Lawyers in America (2015–2025) and Louisiana Super Lawyers (2016, 2022–2024). He was named Baton Rouge Lawyer of the Year in Trademark Law for 2018, 2021, 2023, and 2025. He also serves as a mediator with Perry Dampf Dispute Solutions.
Sonny’s dedication to providing strategic legal solutions has helped countless clients resolve complex disputes, protect intellectual property, and achieve favorable outcomes in litigation. His work exemplifies a commitment to excellence and professionalism in the legal field.
Law Office Affiliations
- Partner, Kean Miller LLP
- Member, Louisiana State Bar, Intellectual Property Section
- Member, American Bar Association, Intellectual Property and Practice Management Sections
Licensed State
- Louisiana
Education
- Louisiana State University
Juris Doctor (JD) - Louisiana State University
Bachelor of Science (BS)
Awards & Badges



- Administrative law
- Antitrust and trade law
- Arbitration
- Banking
- Chapter 11 bankruptcy
- Chapter 13 bankruptcy
- Chapter 7 bankruptcy
- Commercial real estate
- Copyright application
- Copyright infringement
- Corporate and incorporation
- Credit repair
- Debt collection
- Defective and dangerous products
- Employee benefits
- Litigation
- Mediation
- Trademark application
- Trademark infringement