Atty. John J. O'Brien

Atty. John J. O'Brien

John specializes in personal injury, complex business disputes, and sex trafficking litigation. A 14-year lawyer, he has always focused his practice on helping individuals and business owners recover from harm caused by others.

San Diego San Diego 19 yrs experience 19 year
Call (619) 821-5648 Book Appointment

Profile Summary

About John J. O'Brien at a glance

John J. O'Brien is an Associate based in San Diego, California, practicing at Thorsnes Bartolotta McGuire. They have 19+ years of legal experience, licensed to practice since 2007. Their practice focuses on personal injury, business, and litigation. Admitted to practice in California U.S. District Court, Southern District of California U.S. District Court, Northern Distri (2007). Educated at California Western School of Law (J.D., 2007) and Boston College (B.A. Economics, 2003). Active member of Association of Business Trial Lawyers Irish American Bar Association of San Diego Consumer Attorneys of San Diego Consumer Attorneys of California San Diego County Bar Association. Serands clients in San Diego, CA and the surrounding metropolitan area.

Verified attorney profile · Updated June 2026

About

  • John specializes in personal injury, complex business disputes, and sex trafficking litigation
  • A 14-year lawyer, he has always focused his practice on helping individuals and business owners recover from harm caused by others
  • In his signature case to date, John received an Outstanding Trial Lawyer award in Jane Does No. 1-22 v GirlsDoPorn.com, where his clients were awarded $20 million in damages
  • As a result of the case John put together, during the GirlsDoPorn trial, federal authorities indicted the defendants for sex trafficking and conspiracy
  • Raised in Baltimore, Maryland, John graduated from Boston College in 2003 with a degree in Economics and later received his law degree from California Western School of Law in 2007, where he was on the Dean's List and Moot Court Honor's Board
  • Passionate about helping the underdog and mistreated, whether his client is an individual or business, John gives every case the same attention he would afford to a family member or best friend
  • John's plaintiff-focused practice has pursued defendants for personal injury, business fraud, breach of fiduciary duty, infliction of emotional distress, unfair business practices, misappropriation of trade secrets, misappropriation of likeness, breach of contract, and real estate fraud
  • As just a few examples of John's expansive practice, he has successfully prosecuted start-up businesses for deceitful investment opportunities, sellers for concealing the condition of property, and business partners for circumventing partnership opportunities
  • He is currently suing several residential hotels for violations of California's "28-Day Shuffle" law
  • John's wide-ranging case experience allows him to successfully strategize complex cases, resolve novel issues, and exploit defense weaknesses
  • As defendants John sues soon discover, John is a fierce competitor
  • In the GirlsDoPorn case alone, he opposed over 100 motions (including motions to disqualify his team), filed over 30 motions, and took depositions throughout the country
  • Despite GirlsDoPorn's many attempts to derail John from getting the case to trial, the case culminated in a 99-day trial, with 57 witnesses and over 3,000 exhibits
  • John tackles each case with courage, fortitude, and hard work - both in out of the courtroom
  • Outside the office, John fuels his competitive spirit on the ice and at the gym - he is captain of his ice hockey team and is a regular at a local Olympic weightlifting gym
  • Maintaining balance, John enjoys sailing as member of San Diego Yacht Club, hot yoga, live music, and has played guitar since the sixth grade
  • This well-rounded balance enables him to passionately take on opponents, while having compassion for his clients
  • John tackles each case with courage, fortitude, and hard work - both in and out of the courtroom

Practice Areas Explained

John J. O'Brien's Areas of Practice

Each practice area below reflects the types of cases John J. O'Brien handles, with a brief overview of what that area of law covers.

Personal Injury

Personal injury attorneys help accident victims recover compensation for medical bills, lost wages, and pain & suffering. Most work on contingency — no fee unless you win.

John J. O'Brien is one of 264,852 personal injury attorneys indexed nationally. Browse personal injury attorneys in California →

Business & Corporate Law

Business attorneys advise founders and growing companies on entity formation, contracts, financing, M&A, and dispute resolution.

John J. O'Brien is one of 501,317 business attorneys indexed nationally. Browse business attorneys in California →

Civil Litigation

Civil litigation attorneys for breach of contract, business disputes, civil rights, and class action lawsuits.

John J. O'Brien is one of 454,532 litigation attorneys indexed nationally. Browse litigation attorneys in California →

Jurisdictional Context

Why local counsel matters in California

Practicing law in California. Legal matters in California are governed by state-specific rules of civil and criminal procedure, statutes of limitations, and substantive law. Cases originating in San Diego are typically filed in the local municipal court or the appropriate California state district court, depending on subject matter and amount in controversy. An attorney licensed in California brings working knowledge of local procedural deadlines, judicial practices in this andnue, and the substantive law that applies to cases brought here. Out-of-state attorneys generally cannot represent clients in California courts without local counsel or pro hac vice admission.

Looking for additional California attorneys? Browse all attorneys in San Diego or all attorneys in California.

Frequently Asked

Common questions about John J. O'Brien

Where is John J. O'Brien's law office located?
John J. O'Brien's law practice is located in San Diego, California. The firm is Thorsnes Bartolotta McGuire. You can contact the office directly through this profile page.
What practice areas does John J. O'Brien handle?
John J. O'Brien focuses on personal injury, business, litigation. Each practice area listed reflects experience handling cases of that type in California.
How long has John J. O'Brien practiced law?
John J. O'Brien has 19+ years of legal experience and has been licensed since 2007.
Where did John J. O'Brien go to law school?
John J. O'Brien earned their education at (J.D., 2007); (B.A. Economics, 2003).
How can I contact John J. O'Brien for a consultation?
You can contact John J. O'Brien directly through this profile page. Click "Ask the Attorney" to submit a question, or "Schedule a Consultation" to book a meeting. Most claimed-profile attorneys respond within one business day.

Education

J.D.
California Western School of Law
- 2007
B.A. Economics
Boston College
- 2003

Bar Admissions

California U.S. District Court, Southern District of California U.S. District Court, Northern Distri
Admitted: 2007

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