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About me

Legal Education and Background:  Attorney O'Neill came to the La Crosse area from Spring Green Wisconsin in 1988. He attended and graduated from the University of Wisconsin La Crosse with degrees in Political Science and Public Administration near the top of his class.  He attended Drake University Law School and graduated in 1997 with high honors and induction into the Order of Coif (top 10% of his class).   Because of top scores in Evidence and Criminal Practice and Procedure Attorney O'Neill was assigned a clerkship by Professor James Adams to do a State wide survey of Criminal Law.  He was voted by his graduating class as the most likely to become a law professor. 


Legal Experience: Sean has more than 15 years experience as an aggressive trial litigator.  His main focus is representation in criminal and civil matters.  He has assisted numerous persons accused of criminal and drunk driving offenses with excellent results (See case examples).  He also has a successful personal injury practice and has helped numerous injured persons receive the compensation they deserve.   His third major area of practice is family matters such as divorce, child custody and support.  He is a member of the American and Wisconsin Association Justice and the Wisconsin and La Crosse Area Criminal Lawyers Associations. He holds licenses to practice law in Iowa and Wisconsin.  ONeill Law Firm, LLC was formed by Attorney ONeill in 2012 to meet the growing needs of his client base.  


Be sure to look at Attorney O'Neill's case examples.  Every one has a cite to the actual case to insure you that what is being represented is 100% the actual result.  Most all these cases can be researched in the Wisconsin CCAP system. There are no exaggerations or lies here.   No attorney can promise a result.  An attorney who does is not acting ethically.  But these case results amassed over 15 years of aggressive practice show a solid track record.   Its not lost on Attorney O'Neill that you work hard for your money.   He knows word of mouth advertising is the most valuable kind and something no attorney can buy.   You will get competent, aggressive, uncompromising legal representation for your hard earned dollar. 


Community Activities: Sean believes in giving back to his community.  He is a member of the Onalaska Lions Club and a member of the Centering Onalaska Community group. He has guest lectured at both U.W. La Crosse and Western Wisconsin Technical College on issues of Constitutional Law, Criminal Law and Contracts. Sean lives in Onalaska with his wife and three children.


Phone: (608) 519-3551 (Ask for Attorney Sean O'Neill)


Addtional Website:



Languages spoken: Spanish

Photos and videos

1512888 1365031544

Practice areas


  1. Criminal Defense: 50%
    18 years
  2. Family: 30%
    18 years
  3. Chapter 7 Bankruptcy: 15%
    18 years
  4. Personal Injury: 5%
    18 years



Free consultation (30 minutes)

Payment types:

Cash, Check, Credit card

Attorney endorsements

21 total 

Are you an attorney? Endorse this lawyer

  • Molly C. French

    Sean works very hard for his clients. He is thorough and extremely competent.


    Molly French Family Attorney
    Relationship: Fellow lawyer in community

  • No photo

    I have worked with Sean O'Neill in several complex cases over the years, and I am always glad when he is involved because he will not tacitly sit by the sidelines while I work the case. He is skilled in the use of both civil and criminal procedure. Sean is patient with his clients and works hard to advocate their positions. His professional colleagues in this area respect Sean. I endorse this lawyer.


    Kris Wright Family Attorney
    Relationship: Worked together on matter

Contact info

O'Neill Law Firm, LLC

115 5th Ave S #421.
La Crosse, WI, 54601


WIGood Standing199703/23/2015

Professional misconduct

This lawyer was disciplined by a state licensing authority.

  1. Reciprocal - Reprimand
    issued in IA, 2013


    This means that the attorney's misconduct in another state, or jurisdiction, also violated the rules for practicing law in Iowa.

    Sean’s comment: “This is not another reprimand. Its for what transpired in Wisconsin in 2010.”

  2. Public Reprimand
    issued in WI, 2012


    Reprimand means an attorney did something wrong but may still practice law. The State gives the lawyer a public reprimand in hopes that he or she will not repeat the behavior. Details of the infraction are made part of the public record.

    Sean’s comment: “This is extremely misleading. I will talk to anyone who asks about it. Nothing to hide. Look at these real case results, endorsements and testimonials and decide. I one of the best criminal defense lawyers in the area and I can prove it. Shows how utterly flawed Avvo's ratings system is. I was once a 7.5 rated, then this nonsense.”

Avvo contributions
Legal answers
Award nameGrantorDate granted
Outstanding Leadership AwardBNI1999
Order of the CoifDrake Law School1997
Law Professor AwardDrake Law Class 19971997
Work experience
TitleCompany nameDuration
OwnerONeill Law Firm, LLC2012 - Present
Associate PartnerFehr Law Office2002 - Present
AssociateAblan Law Firm1999 - 2002
AssociatePark O'Flaherty1997 - 1999
Association namePosition nameDuration
Centering OnalaskaMember2001 - Present
Onalaska Lions ClubMember2000 - Present
American Trial Lawyers AssociationMemberN/A
Wisconsin Academy of Trial LawyersMemberN/A
La Crosse Area Criminal Lawyers AssociationMemberN/A
Wisconsin Criminal Lawyers AssociationMemberN/A
Legal cases
Case nameOutcome
State v. William OgdenAcquittal
State v. Peter A. KrumpJury Acquittal
State v. Erwin BeckomMajor Felony to Possession
See all legal cases 
Publication nameTitleDate
AVVOChild Custody and Placement-- What you should know2011
Drake Annual Survey of Criminal LawSurvey of Iowa Criminal Law1997
School nameMajorDegreeGraduated
Drake University Law SchoolLawJD - Juris Doctor1997