- The Florida Bar
- U.S. District Court, Middle District of Florida
- U.S. District Court, Southern District of Florida
Overview
Cassidy Mandelbaum focuses her litigation practice on commercial disputes and intellectual property matters, including trademark and copyright litigation in Florida’s federal and state courts. Her work spans discovery strategy and disputes, protective order practice, and motion drafting from filing through resolution. Cassidy has prepared and filed trademark applications before the USPTO, guiding clients through the application, examination, and registration process, including 2(d) likelihood of confusion office action responses and specimen advisory. Clients value working with Cassidy for her accessibility and clear communication. She stays reachable throughout a matter and explains legal strategy in plain, straightforward terms. She works to give clients a sense of comfort, security, and control over their matter.
Cassidy earned her Juris Doctor from Washington University in St. Louis School of Law in May 2025. As a law student, she was a member of the Global Studies Law Review, received the William M. Pomerantz Award for her performance in the INTA Saul Lefkowitz Trademark Moot Court Competition, and worked in the First Amendment Clinic representing clients in speech-rights matters.
Before joining Jimerson Birr, Cassidy was a Legal Intern at the U.S. Attorney’s Office for the Middle District of Florida, Jacksonville Division, where she gained trial experience from filing through sentencing across the criminal litigation process.
A Jacksonville-area native from Fernandina Beach, Cassidy is a triple Gator: she holds a bachelor’s degree in marketing, a bachelor’s degree in Tourism, Hospitality, Event and Sport Management, a minor in real estate, and an MBA in Marketing, all from the University of Florida. She returned to Northeast Florida after law school to practice in her home community.
Outside the office, Cassidy is an artist and children’s book author.
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Bar and Court Admissions
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Education
- Washington University in St. Louis School of Law, Juris Doctor
- University of Florida, Master of Business Administration in Marketing
- University of Florida, Bachelor of Science in Marketing; Bachelor of Science in Tourism, Hospitality, Event and Sport Management; Real Estate Minor; Honors
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Representative Matters
- Advised a trademark owner on enforcement against multiple defendants.
- Asserted Lanham Act, trade secret, contract, and unfair trade practices claims in a pre-suit demand on behalf of a business against a former employee’s competing venture.
- Drafted motions to suspend proceedings and extend time in a TTAB cancellation proceeding paired with a federal trademark action in the Southern District of Florida, on behalf of the registrant.
- Defended a company and its officers in a federal intellectual property infringement action in the Middle District of Florida.
- Overcame a USPTO Section 2(d) likelihood-of-confusion refusal citing four marks and secured registration for a consumer packaged goods brand.
- Prepared trademark clearance opinion letters and advised on registration strategy, including for marks with foreign-language meanings.
- Represented a defendant in a design patent infringement action in the Southern District of Florida with a negotiated resolution.
- Successfully defended against a pre-suit copyright infringement demand.
PRIOR RESULTS DO NOT GUARANTEE A SIMILAR OUTCOME
Industries
Services
- Appeals
- Administrative Law and Licensing
- Arbitration & Mediation
- Bet The Company Litigation
- Business Litigation
- Business Process Consulting
- Corporate Formation, Transactions and Dissolution
- Corporate and Board of Directors Governance and Operations Counsel
- Disaster and Crisis Preparation and Response
- Environmental Diligence, Compliance, Permitting and Mitigation
- General Counsel for Small Businesses or Start Up Companies
- Intellectual Property Protection
- Florida Shareholder Dispute Attorneys
- Subpoena Response
- Trade Secret Protection
- Vendor Contracting
- Workplace Safety, OSHA and CDC Compliance
- College Athlete Name, Image, and Likeness
News
Jacksonville, FL – Jimerson Birr is proud to announce the return of six new attorneys: Olivia A. “Liv” King, Cassidy M. Mandelbaum,…
