Colleen M. O'Neil
Attorney Profile
Top Rated Business Litigation Attorney in Cleveland, OH
Selected to Rising Stars: 2009
Colleen O’Neil serves as Co-Chair of Calfee's Litigation practice group. She helps clients resolve complex business disputes.
Colleen has extensive experience in federal and state courts nationwide helping business clients resolve the following:
- Commercial contract disputes
- Shareholder and corporate disputes, including post-closing issues
- Estate and probate matters
- Trade secret claims
- Real property disputes
- Municipal and public law issues
- Title VII claims
Colleen has counseled and represented businesses, financial institutions and high-net-worth individuals in a variety of corporate, commercial, fiduciary and employment disputes with a results-oriented, practical approach.
She has successfully prosecuted and defended a variety of business tort claims in both federal and state courts nationwide.
Colleen has represented municipalities and clients in the energy industry in various types of litigation, including contractual disputes, real estate disputes and employment matters.
Colleen has been selected for inclusion to the Ohio Super Lawyers list from 2012-2021. She has also been named to the Top 50 Women Ohio Super Lawyers list from 2013-2021 and as a Top 25 Women Cleveland Super Lawyers list from 2013-2018 and 2020-2021.
She joined Calfee in 1998, and she is a member of the firm’s Practice Planning and Growth Committee and the Diversity & Inclusion Committee. Colleen began serving as Vice Chair of the firm's Litigation practice group in 2019 and Co-Chair in 2021.
Top Lists
- Top 50: 2022 Women Ohio Super Lawyers
- Top 25: 2022 Women Cleveland Super Lawyers
- Top 50: 2021 Women Ohio Super Lawyers
- Top 25: 2021 Women Cleveland Super Lawyers
- Top 25: 2020 Women Cleveland Super Lawyers
- Top 50: 2020 Women Ohio Super Lawyers
- Top 50: 2019 Women Ohio Super Lawyers
- Top 50: 2018 Women Ohio Super Lawyers
- Top 25: 2018 Women Cleveland Super Lawyers
- Top 50: 2017 Women Ohio Super Lawyers
- Top 25: 2017 Women Cleveland Super Lawyers
- Top 25: 2016 Women Cleveland Super Lawyers
- Top 50: 2016 Women Ohio Super Lawyers
- Top 50: 2015 Cleveland Super Lawyers
- Top 25: 2015 Women Cleveland Super Lawyers
- Top 100: 2015 Ohio Super Lawyers
- Top 50: 2015 Women Ohio Super Lawyers
- Top 100: 2014 Ohio Super Lawyers
- Top 50: 2014 Women Ohio Super Lawyers
- Top 50: 2014 Cleveland Super Lawyers
- Top 25: 2014 Women Cleveland Super Lawyers
- Top 100: 2013 Ohio Super Lawyers
- Top 50: 2013 Women Ohio Super Lawyers
- Top 50: 2013 Cleveland Super Lawyers
- Top 25: 2013 Women Cleveland Super Lawyers
About Colleen M. O'Neil
First Admitted: 1996, Ohio
Professional Webpage: https://calfee.com/professionals/colleen-m-oneil/
Educational Background
- J.D., magna cum laude, Cleveland-Marshall College of Law., 1996
- B.A. John Carroll University, 1992
Honors/Awards
- Ohio Super Lawyer, Top 50 Female Lawyers in Ohio, Top 25 Female Lawyers in Cleveland, Ohio Super Lawyers, 2021
- The Best Lawyers in America, Commercial Litigation, The Best Lawyers in America©, 2021
- Woman of Professional Excellence Award, YWCA of Greater Cleveland, 2010
Bar/Professional Activity
- Cleveland-Marshall College of Law Board of Visitors, Member, 2021
- Irish American Law Society of Cleveland, Founding Member, Former Vice President, 2021
- Magnificat High School, Chair, Board of Directors, May 2017 to present, 2021
- Cleveland Marshall Law Alumni Association, Board Member, 2021
- American Bar Association and the ABA’s Litigation Section, Member, 2021
- Ohio Bar Association, Member, 2021
- Cleveland Metropolitan Bar Association, Member, 2021
- U.S. Court of Appeals for the Fifth Circuit
- U.S. Supreme Court
- U.S. Court of Appeals for the Eighth Circuit
- U.S. Court of Appeals for the Sixth Circuit
- U.S. Court of Appeals for the First Circuit
- Supreme Court of Ohio
- U.S. District Court for the Southern District of Ohio
- U.S. District Court for the Northern District of Ohio
- Ohio
Industry Groups
- Energy And Utilities
- Health Care
- Private and Family-Owned Businesses
- Public Companies
- Real Estate.
Additional Sources of Information About Colleen M. O'Neil
Visit my FindLaw® profile
Last Updated: 5/15/2022