Attorney Profile

Attorney Sean M. Sweeney

Attorney Sean M. Sweeney has the requisite skills, education, and experience to help serve all of your legal needs in the Milwaukee area.

Sean earned his Juris Doctor (JD) and Masters of Business Administration (MBA) from Marquette University. He earned his Bachelor of Science degree in Business Economics from Northern Arizona University and is now a partner with Halling & Cayo, S.C. 

Before joining Halling & Cayo, Sean ran his own practice, Tosa Law Office. Sean has experience drafting contracts ranging from small business contracts to plow a parking lot to large corporation contracts dealing with operating and maintaining real estate, litigating business disputes as both plaintiff’s and defendant’s counsel, helping buyers and sellers complete real estate transactions, and representing investors and stockbrokers in securities litigation..

In 2011 through 2017 Sean was named to the Wisconsin Super Lawyers® Rising Stars list as one of the top attorneys in Wisconsin. No more than 2.5% of the lawyers in the state are selected to the list. In 2012, 2013, 2014, 2015, and 2016 (before it was discontinued) Sean was also named to M: Milwaukee’s Lifestyle Magazine’s Leading Lawyers for Litigation. Leading Lawyers only selects those attorneys ranked in the top 2-5% for each category. In 2013, Sean was named to the Wisconsin Law Journals selection of Up-And-Coming Lawyers. 

Sean not only has the legal training and experience needed to provide complete service, he also has the education and training to understand the real world needs and challenges that organizations large and small face today.

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 Speaking Engagements

  • Contract Law overview, Guest Lecturer, Waukesha County Technical College (2014)
  • LLCs From a Litigator’s Prospective – Avoiding Litigation, Lorman Education Services (2013)
  • LLCs From a Litigator’s Prospective – Resolving Litigation, Lorman Education Services (2013)
  • Investment Fraud, from Wall Street to Main Street, Milwaukee Bar Association Presents (2012)
  • FINRA Mediation and Arbitration, State Bar of Wisconsin Litigation, Dispute Resolution & Appellate Practice Institute (2012)
  • Hidden Gems in Adobe Acrobat, Wisconsin Solo and Small Firm Conference (2011)
  • Ethics of Social Media, Wisconsin Solo and Small Firm Conference (2010)
  • Using Blogging as an effective communication tool, Wisconsin Bar Leaders Conference (2009)
  • Negotiating the Transition from Law School to Practice, Marquette University (2008)

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Marquette University Law School– Juris Doctor

Marquette University School of Business– Masters of Business Administration

Northern Arizona University– Bachelor of Science in Business Economics

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Legal Community Involvement
Milwaukee and Waukesha County Public Defenders Appointments: When Sean first graduated from law school, he represented clients as a Public Defender appointed Attorney in both Milwaukee and Waukesha counties. The public defender’s office provides legal assistance to those people charged with a crime who do not have the means to pay for counsel on their own. Often times the Public Defenders Office is not able to adequately serve all of the people who need assistance, therefore attorneys such as Sean while with Tosa Law Office took some of the surplus cases to help ease the burden on the often overtaxed public defenders office. Sean took part in a large number of probation and extended supervision revocation cases, as well as defense work in Mental Health commitments.

Guardian Ad Litem’s Office: While in Law School Sean worked for the Guardian Ad Litem’s Office in the Children’s Court. While there, he worked on cases involving Children in Need of Protective Services actions as well as Termination of Parental Rights actions. Sean also researched extensively and helped prepare for a Wisconsin Supreme Court case involving a Termination of Parental Rights action.

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Community Service
Big Brothers Big Sisters: Sean has been a Big Brother through the Big Brothers Big Sisters organization in Milwaukee from July of 2007 to July of 2011. Sean was placed with a little brother. They have had a lot of fun together and the experience has shown to be very rewarding for both Sean and his little brother. As a personal recommendation, I would ask that anyone who has the time, (just a few hours a month) should sign up to be a big brother or big sister. I do not know of any other way to more significantly impact a young persons life than to simply take an interest and help teach him/her how to feel good about themselves and be successful in life. This request comes double for men to be big brothers as there is always a shortage of big brothers vs. big sisters.

North Central Little League: Sean was a volunteer coach in 2011, 2012, and 2013 for the NCLL Juniors baseball program. Sean coached kids from the North side of Milwaukee and Wauwatosa for ages 13-15. For the players it was their transition to full baseball, on a 90 foot diamond, before high school baseball. The team focused on not just refining their skills but also learning the rules of the game, and most importantly, having fun. After Sean’s second son was born in 2014, he retired until his boys were old enough to play, and now has started through the ranks again coaching t-ball and moving on up.

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