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William J Duffy V
also known as Bill
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About William
Biography
William J. Duffy V is a distinguished criminal defense attorney based in Orange County, California, renowned for his expertise in DUI defense and domestic violence cases. He previously served as a Certified Law Clerk for the Los Angeles County District Attorney, gaining invaluable insights into prosecutorial processes that benefit his clients. As the managing partner of Duffy Law’s Irvine office, Bill capitalizes on a broad spectrum of trial experience developed both locally and with other elite Southern California law firms. He is committed solely to defending clients in Orange County who face criminal charges, guiding them through each phase of the legal process, from investigations and pre-trial motions to litigation in court. Clients count on Bill for his assertive defense approaches, comprehensive knowledge of California’s criminal statutes, and personal pledge to achieve positive case results. For a proficient Orange County criminal defense lawyer who understands your specific needs and staunchly defends your rights, reach out to Bill for professional legal representation.
Facing DUI or Domestic Violence charges in Irvine or Newport Beach? Trust Orange County defense attorney William J. Duffy V and Duffy Law for proven criminal jury trial experience and local expertise with judges and prosecutors to fight for the best outcome in your case.
Facing criminal charges in Irvine or Newport Beach? Trust Orange County defense attorney William J. Duffy V and Duffy Law for proven criminal jury trial experience and local expertise with judges and prosecutors to fight for the best outcome in your case.
With over 18 years of experience, Orange County attorney William J. Duffy has a proven track record—winning over 75% of his 25+ DUI jury trials with not guilty verdicts or hung juries. If you’ve been charged with DUI, trust Duffy Law for aggressive, results-driven defense.
Accused of domestic violence in Irvine? Orange County attorney William J. Duffy delivers aggressive defense, local expertise, and proven results to protect your rights and future. Get experienced help with your case at Duffy Law today.
Practice Areas
3
Practice Areas
Criminal Defense
40%
18 years
DUI and DWI
40%
18 years | 750 cases
Domestic Violence
20%
18 years | 400 cases
Fees and Rates
Cost
Hourly Rates
$ 450-450 per hour
Retainer
Always
Payment Methods
- Cash
- Check
- Credit Card
Licenses
Licensed in California for 18 years
State: California
Acquired: 2007
No misconduct found
Location
William Duffy
(949) 536-8809
Mobile
100 Spectrum Center Drive, Suite 900, Irvine, CA, 92618
willduffy.law/Gallery
Online Presence
Other places you can find William online.
William J Duffy V's Reviews
Showing 1 - 5 of 34 client reviews from Avvo
Posted by John | October 4, 2025 | Consulted Attorney
This review is from a potential client who consulted with this attorney.
Top marks to William from Duffy Law in OC, CA
William goes above and beyond the call of duty! We have had the pleasure of collaborating on a few different projects. William is hardworking, insightful, results driven, and is truly on your side. If you are looking for a lawyer in Irvine, William Duffy warrants your attention. Check him out at http...
Posted by Candis | November 6, 2022 | Hired Attorney
This review is from a person who hired this attorney.
Thanks Duffy
Left message for Duffy that boyfriend was bailing out of jail and needed a lawyer asap. He called me back right away and represented my boyfriend on a very complicated case. Duffy is a very professional and knowledgeable criminal defense lawyer. He was able to get my boyfriend a very fair deal for th...
Posted by CJ | December 13, 2020 | Hired Attorney
This review is from a person who hired this attorney.
Mr. Duffy is great!
I have worked with William Duffy on two related occurrences: initial handling of a DUI and a recently the expungement of that same DUI. Duffy and team were very clear with what where I stood, timelines, and expected outcomes. He was able to get an incredible outcome for me in the initial case and a q...
William Duffy
Replied last December 21, 2020Thanks, CJ! We are glad you were satisfied and are here if you need anything.
Posted by Brian | March 12, 2020 | Hired Attorney
This review is from a person who hired this attorney.
Amazing lawyer
Mr. Duffy has been an amazing lawyer. He took the time out to make sure I completely understood my situation and what we could do to get the best result. Also took the time to speak with my family and kept them up-to-date with the whole situation . He worked very hard on my case and got me a deal t...
Posted by Kyle | March 7, 2020 | Hired Attorney
This review is from a person who hired this attorney.
Excellent
I hired Mr. Duffy when I was charged with a D.U.I. He welcomed me into his extended family. I feel comfortable and confident with his sincerity to want to help.
William J Duffy V's Lawyer Endorsements
"I highly endorse Bill Duffy. In my 30 years as an attorney, I have not met an attorney with a higher degree of character and integrity than Bill. He deeply cares about his clients and puts his clients' concerns and welfare first. He is a strong advocate and works very hard to achieve the best result for his clients, yet he is very practical and pragmatic in his approach."
"Fantastic attorney. I have seen him fight hard for his clients. I absolutely endorse this attorney"
"Bill is a wonderful attorney. I have worked with Bill and seen first hand how he fights for his clients and how experienced and talented he is in a courtroom. I endorse this lawyer."
"William is an exceptional attorney. He knows the law, the judges, and the DA’s. You can’t ask for better representation on a DUI."
"I endorse this lawyer. Mr. Duffy is a talented, experienced, and skillful DUI defense attorney. He has a solid reputation for analyzing every piece of evidence and employing the best possible strategies to exploit the specific weaknesses in his client's DUI cases."
"I've known Mr. Duffy since law school, when we studied together regularly. His commitment has inspired me ever since. I have had the opportunity to review some client matters for a second opinion after the client worked with Mr. Duffy. In each of those matters, Mr. Duffy obtained the absolute best result possible under the circumstances. In one case, his efforts spared the client from 22 years in state prison after a string of armed robberies. Based on the top-quality work I've seen in his cases, I heartily recommend him."
"Mr. Duffy is an excellent criminal defense attorney that is specialized in DUI defense. He is extremely professional and treats his clients as if they were family. As a colleague he is extremely helpful and has given me excellent advice on my DUI cases over the years. I highly recommend Mr. Duffy for any criminal case you may have."
"I endorse this lawyer."
"I endorse this lawyer."
"I endorse this lawyer."
"I endorse this lawyer."
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Experience
Honors
2020
Featured Attorney, Lawyers of Distinction
2020
Peer Review Rated, Martindale-Hubbell
2019
Featured Attorney, Lawyers of Distinction
2019
Peer Review Rated, Martindale-Hubbell
2018
Featured Attorney, Lawyers of Distinction
2004
Witkin Scholarship Award - Civil Procedure, Witkin
2004
Witkin Scholarship Award - Torts, Witkin
Work Experience
2017 - Present
Managing Attorney, Law Offices of Todd Landgren (C.A.R. Law, P.C.)
2017 - Present
Managing Attorney, Duffy Law, P.C.
2011 - 2017
Managing Attorney, Law Offices Of Myles L. Berman (Top Gun DUI)
2008 - 2011
Attorney, Law Offices of William J. Duffy
2008 - 2009
Attorney, Shouse Law Group
2007 - 2008
Attorney, San Bernardino County Public Defender
2004 - 2007
Certified Law Clerk, Los Angeles County District Attorney
Associations
2016 - Present
Newport Harbor Bar AssociationMember
2009 - Present
North Orange County Bar AssociationMember
2009 - Present
California DUI Lawyers AssociationMember
2007 - Present
Orange County Bar AssociationMember
2007 - Present
National Association of Criminal Defense LawyersMember
2017 - 2018
West Orange County Bar AssociationVice President
Sample of Legal Cases
People v. Contreras
DMV Set Aside of Suspension Action
People v. Lauer
2nd DUI-Drugs/Accident Case Dismissed
Education
2006
Western State University College of Law
JD - Juris Doctor
1994
University of Montana-Missoula
BA - Bachelor of Arts
Publications
2017
California Criminal Law - Procedure and Practice
DRIVING UNDER THE INFLUENCE CASES
Languages
English
Activity
Legal Answers
Legal Answers
Q&A
What will happen if it’s my first time shoplifting and I got caught ? The LP told me something about a letter ?
19 Nov 2018
Q&A
Do I have to be present for sentencing for first time DUI?
19 Nov 2018
Q&A
Blood test came back 0.09% how likey will my case be dropped?
21 May 2018