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Jeffrey Merton O'Holleran

Criminal defense Attorney at Cheyenne, WY

5.0   2 reviews

also known as Jeff O'Holleran, Jeffrey OHolleran

  • State Years
    Wyoming - WY 7 years
    Nebraska - NE 8 years
    Colorado - CO 13 years
  • Licensed for 7 years
    State WY
    Acquired 2016
    Active No misconduct found
  • Licensed for 8 years
    State NE
    Acquired 2014
    Inactive No misconduct found
  • Licensed for 13 years
    State CO
    Acquired 2010
    Inactive No misconduct found

We have not found any instances of professional misconduct for this lawyer.

About Jeffrey

Learn Jeffrey’s areas of practice.

Practice areas
  1. Criminal defense
    Jeff O'Holleran worked as an trial attorney for the Denver Office of the Colorado State Public Defender from 2011-2013 before going into private practice. He currently works as an assistant district attorney for the First Judicial District in Wyoming

    13 years, 1,800 cases

  2. Business
    Jeff O'Holleran has handled upwards of 6000 business filings including new business filings, amendments, trademark and trade name prosecution, in addition to advising on matters of corporate structure and governance.

    9 years, 6,000 cases

  3. Government
    Having worked at the Wyoming Secretary of State, much of his practice involves statutory and constitutional interpretation, rule-making, and securities and business regulation.

    9 years

Jeffrey O'Holleran has had a successful career as a criminal defense attorney both in government and private practice. He attended the University of Colorado where he earned a BA in Psychology and his Juris Doctor. While at law school he worked as a Production Editor for the Journal on Telecommunications and High Technology Law.

Jeffrey currently works for the First Judicial District in Wyoming as an assistant district attorney and is part of the faculty at the University of Colorado at Boulder.

In his spare time, Jeffrey is a programmer. He has written on the subject, having published an article on the history of video game censorship. His work was cited in a brief submitted to the U.S. Supreme Court in the case of Schwarzenegger v. Entertainment Mercants Association.

Photos and videos

The O'Holleran Law team

Contact Jeffrey

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District Attorney, First Judicial District of Wyoming
320 E 19th Street, Suite 200
Cheyenne, WY, 82001


5.0 / 5.0
  2 customer reviews
5 Star
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1 Star
Posted by Barbara | March 19, 2014
Grateful to you Mr. OHolleran
I can not begin to explain how grateful I am to have Mr. O'Holleran represent me in my situation at hand. My situation is complex, it is huge, it is over whelming, it is bigger then me and beyond my knowledge as a citizen trying to live with in our community. It has consumed me and it has taken over my life. I have been dealing with my situation for 1 year and 4 months now. The day I asked Mr. O'Holleran if he could and would help me is the very day I learned that I still am worthy of having someone in my life who cares about what I am going through. For me caring about ones situation no matter what it is that your up against is of one of the most important tools to have in life. I have found this in Mr. O'Holleran. His knowledge of law and how the process of defending someone is unexplainable for me. He is caring, professional and he is quick, and he gets results to your comfort level and to his own. We are not yet finished with my situation at hand, so this is to be continued for I would like to share again with anyone who reads this my final out come. I am confident it will end up with a graceful walk for me in my future because Mr. OHolleran chose to walk with me, not behind me, not in front of me but along my side. Mr. OHholleran Thank you for representing... To be continued For Ever Grateful Barbara
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Posted by anonymous | January 15, 2014
Best of the best.
I have relied upon Jeff O’Holleran on several occasions. His knowledge of the law is first rate. He advised me when I represented myself in traffic court. I defeated the city attorney and got the case dismissed. He later prevented me from having a felony on my record. In both cases, he took the time to explain my options and to outline what each course of action would entail. I have found that his prudent thinking and good decision-making are his greatest strengths. I always feel fully informed of the possible outcomes of each decision that I make along the way, and Mr. O’Holleran always works to get the best possible outcome in each situation. I am also impressed by his previous experience. He is able to use elements from previous and similar experiences to great effect. And, when the case is over he has always explained what is expected of me going forward. He is always available when I call and his staff is so friendly, I know that I can count on Mr. Oholleran to give my case the defense I deserve.
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AVVO RATING 9.5 (Superb)

Work Experience

  • Assistant District Attorney
  • Office of the District Attorney, First Judicial District
  • 2019 - Present
  • Managing Partner
  • O'Holleran Law Group, LLC
  • 2013 - Present
  • Member of the Task Force on Special Districts
  • Wyoming State Legislature
  • 2016 - 2016
  • Senior Auditor, Assistant Director of the Business Division
  • Wyoming Secretary of State
  • 2015 - 2019
  • Adjunct
  • University of Colorado
  • 2015 - 2018
  • Deputy Public Defender
  • Colorado State Public Defender
  • 2011 - 2013
  • Certified Student Attorney
  • Colorado State Public Defender
  • 2010 - 2010
  • Law Clerk
  • Attorney General Of Wyoming
  • 2009 - 2009
View all work experience


  • University of Colorado School of Law
  • JD - Juris Doctor
  • 2010
  • University of Colorado - Boulder
  • BA - Bachelor of Arts
  • 2007

Legal Cases

  • People v. E.R.
  • Not guilty at trial
  • People v. C.S.
  • Misdemeanor assault plea
  • People v. C.T.
  • Case dismissed
View all legal cases


  • Colorado Bar Association
  • Member
  • 2010 - Present
  • Journal on Telecommunications and High Technology Law
  • Production Editor
  • 2008 - 2010
  • Intellectual Property Society - University of Colorado Chapter
  • Vice President
  • 2008 - 2010
  • Federalist Society - University of Colorado Chapter
  • Treasurer
  • 2007 - 2010
  • Flatirons Review
  • Production Editor
  • 2004 - 2008
View all associations

Languages Spoken

  • Spanish
  • English
  • Hebrew

Honors and Awards

  • Public Interest Service Award
  • University of Colorado School of Law
  • 2010


Speaking Engagements

  • Taking Protective Custody: A Guide for Medical Providers
  • Protective Custody and Shelter Care of Minors in Wyoming
  • 2021
  • Topics in Blockchain, 2021
  • Business Entity Formation in the Cryptosphere
  • 2021
  • Private Conference
  • Legal Issues Surrounding Blockchain Formation
  • 2020
  • Presentaiton for state and federal law enforcement agents
  • Blockchain for Law Enforcement
  • 2018
  • Two Hats, One Head, No Problem: Navigating Compliance Issues for Attorneys Acting As Registered Agents
  • Maintaining concurrent law and registered agent practices
  • 2018
  • FILM 2003: Special Topics
  • Film and the Law
  • 2015
  • Speaking Event for the Colorado State University Department of Sociology - Criminal Justice Organization
  • A Guide to Police Encounters
  • 2014
  • La Ley Radio, KJJD 1170 AM
  • Legal Q&A with Attorney Jeff O
  • 2014
  • Public Defender Training
  • County Court Basics
  • 2013
  • Public Defender Training
  • How Not To Screw Up In County Court
  • 2012
  • Terrorism Policy with Dr. Harvey Kushner
  • American-Israeli Policy on Radicalism
  • 2008
  • Status of the War on Terror and the Iraq War
  • American-Islamic Relations
  • 2007
View all speaking engagements

Attorney endorsements

Received (5)
Given (9)
Endorse Jeffrey
Criminal defense Attorney | Apr 29
Relationship: Worked together on matter
"Jeffrey is an excellent attorney. When he speaks in court, people listen. I worked alongside Jeffrey as a public defender, and I was invariably amazed by his profound ability to immediately earn the trust of his clients, his effectiveness in persuading the judge, and his sound credibility in speaking to members of a jury. Jeffrey is a unique type of litigator in that he is an "outside-of-the-box" thinker, which is a powerful approach in defending an individual accused of a crime."
Criminal defense Attorney | Jun 06
Relationship: Fellow lawyer in community
"I endorse Jeffrey. He is a highly skilled attorney that is well respected in the legal community."
Criminal defense Attorney | Apr 09
Relationship: Other
"Jeff and I went to law school together. He is a very bright and competent lawyer, who cares deeply about his clients and obtaining the very best results. If I needed a criminal lawyer in Colorado, I'd call Jeff!"
Criminal defense Attorney | Jan 08
Relationship: Co-worker
"Jeff is an agile and skilled attorney who has the background and knowledge to handle any criminal matter that comes his way. I have known Jeff for several years, and personally observed his skill in the courtroom and the quality of his representation. I would not hesitate to refer any of my clients his way."
Criminal defense Attorney | Dec 23
Relationship: Co-worker
"As my next-door neighbor at the Denver Trial Office of the Public Defender, Jeff and I spent a lot of time talking about cases and brainstorming how to best help our clients. There were many nights when most everyone else had gone home that Jeff was still at work figuring out how to best help his clients. He is passionate and clearly cares about getting the best outcome for those he represents."