What does Mark J. O'Brien specialize in?

Mark J. O'Brien specializes in Criminal Defense, White Collar Criminal Defense in Tampa, Florida.

Where does Mark J. O'Brien practice?

Mark J. O'Brien practices at Mark J. O'Brien, P.A. in Tampa, Florida.

Is Mark J. O'Brien a Haute Lawyer member?

Yes. Mark J. O'Brien is independently reviewed and editorially featured by Haute Living as part of the Haute Lawyer Network.

What types of cases does Mark J. O'Brien handle?

Mark J. O'Brien handles Criminal Defense, White Collar Criminal Defense for clients in Tampa and Florida.

Is Mark J. O'Brien accepting new clients?

To inquire about representation, use the contact form on this profile page to send Mark J. O'Brien a message directly.

Mark J. O'Brien

Criminal Defense Lawyer · Mark J. O'Brien, P.A. · Tampa, Florida

Mark J. O'Brien is a criminal defense attorney in Tampa, Florida featured by Haute Lawyer Network. This profile highlights their legal focus, professional background, Attorney Talk features, and contact information.

About Mark J. O'Brien

Mark J. O'Brien, Esquire, is the founder and managing partner of O'Brien Hatfield, PA, a criminal defense law firm based in Tampa, Florida, that focuses on nationwide federal criminal defense and statewide criminal defense and criminal appeals.

Mark has practiced criminal law exclusively since 1998. He began his career as a prosecutor in the Miami-Dade County State Attorney's Office, rising through the ranks before transitioning to defense work. As a former Federal and State Prosecutor, Mark brings invaluable insider knowledge of how the government builds and prosecutes criminal cases.

Mark handles federal criminal cases in federal courts statewide and throughout the United States. He is widely lauded by federal judges and federal prosecutors as one of the best federal defense attorneys in Florida. His practice encompasses white collar criminal defense, federal investigations, healthcare fraud defense, drug trafficking defense, and complex criminal matters at both the state and federal level.

Practice Focus

Mark J. O'Brien concentrates on Criminal Defense and White Collar Criminal Defense.

Professional Background

Mark J. O'Brien practices with Mark J. O'Brien, P.A..

Their professional title is Criminal Defense Lawyer.

Mark J. O'Brien is a verified member of the Haute Lawyer Network, the invitation-based attorney platform operated by Haute Living. Membership requires editorial review by the Haute Living team and inclusion does not constitute a recommendation, endorsement, or guarantee of any specific outcome.

Markets Served

Mark J. O'Brien accepts inquiries from clients in Tampa, Florida. The exact scope of representation, jurisdiction, and engagement terms are determined directly between the prospective client and the attorney.

This profile is part of the curated Haute Lawyer directory, alongside other criminal defense attorneys reviewed by the editorial team at Haute Living.

Verified Profiles

Attorney Talk Features by Mark J. O'Brien

Mark J. O'Brien: Federal Criminal Defense Excellence Built on Prosecutorial Experience · 2025-09-16 — In the high-stakes world of federal criminal defense, where careers, reputations, and freedom hang in the balance, few attorneys command the respect and recognition that Mark J. O'Brien has earned through decades of dedicated practice.

Contact Mark J. O'Brien

Firm: Mark J. O'Brien, P.A.
Address: 511 West Bay Street, Suite 330, Tampa, Florida 33606
Phone: (813) 440-2347
Email: mjo@markjobrien.com
Website: https://www.markjobrien.com/

Frequently Asked Questions about Mark J. O'Brien

Is this profile legal advice?

No. This profile is for general informational purposes only and does not constitute legal advice or create an attorney-client relationship.