Atty. Gregory W. "Greg" Lyons

Atty. Gregory W. "Greg" Lyons

Greg represents clients in the prosecution and defense of complex commercial litigation. His extensive experience in commercial litigation has prepared him to successfully represent large corporations as well as small businesses and individuals.

Call (414) 276-5000 Book Appointment

Commercial Litigation & More Attorney · Serving Milwaukee, WI

Profile Summary

About Gregory W. "Greg" Lyons at a Glance

Gregory W. "Greg" Lyons is a business, litigation, and insurance attorney based in Milwaukee, Wisconsin, practicing at O'Neil, Cannon, Hollman, DeJong & Laing SC. Admitted to practice in Wisconsin, State Bar of Wisconsin. Educated at Marquette University (J.D., 1988). Recognitions include Best Lawyers in America — Commercial Litigation (2026), Best Lawyers in America — Litigation - Insurance (2026), and Best Lawyers in America — Additional Areas of Practice: (2026). Serves clients in Milwaukee, WI and the surrounding metropolitan area.

Verified attorney profile · Updated October 2026

About Gregory W. "Greg" Lyons

Greg represents clients in the prosecution and defense of complex commercial litigation. His extensive experience in commercial litigation has prepared him to successfully represent large corporations as well as small businesses and individuals.

Greg also has extensive experience representing individuals in inheritance litigation. He has successfully litigated many will contests and trust disputes throughout Wisconsin. Greg has accomplished tremendous results on behalf of trustees, personal representatives, and power of attorneys in large complicated disputes.

Greg has appeared in state and federal courts in numerous jurisdictions including California, New York, Texas, Arizona, Oregon, Florida, Illinois, and Washington D.C. Greg is a member of the Wisconsin state and federal courts, Seventh Circuit Court of Appeals, and the United States Supreme Court. Greg also serves as the Chairperson of the firm’s Ethics Committee.

Greg Assists Clients With

  • Inheritance Litigation
  • Will Contests
  • Trust & Estate Litigation
  • Complex Litigation
  • Commercial Litigation
  • Personal Injury
  • Products Liability Litigation
  • Insurance Coverage Litigation
  • Class Action Litigation
  • General Business Counseling
  • Contract Disputes
  • Tort Disputes
  • Appellate Practice

    Professional Associations & Affiliations

  • Life Fellow, American Bar Foundation
  • State Bar of Wisconsin
  • Eastern District of Wisconsin Bar Association
  • Milwaukee Bar Association
  • Waukesha County Bar Association
  • Ozaukee Bar Association
  • Waukesha County Business Alliance
  • Independent Business Association of Wisconsin

    Court Admissions

  • Wisconsin
  • U.S. District Court, Eastern District of Wisconsin
  • U.S. District Court, Western District of Wisconsin
  • U.S. Court of Appeals, Seventh Circuit
  • U.S. Supreme Court
  • Various other state and federal courts across the U.S. on a pro hac vice basis

    Awards/Distinctions

  • Named 2022 Best Lawyers® “Lawyer of the Year” for Litigation–Insurance
  • Named 2022 Attorney of the Year by Top 100 Registry
  • Martindale-Hubbell® Peer Review Rating™–AV Preeminent, reflecting an attorney who has reached the height of professional excellence and is recognized for the highest levels of skill and integrity
  • Selected for inclusion in The Best Lawyers in America®–Commercial Litigation in 2014 and Commercial Litigation and Litigation–Insurance in 2015–present
  • Selected as a Member of The Nation’s Top One Percent by the National Association of Distinguished Counsel, whose rosters “Consists of the leading legends of the legal profession”
  • Fellow with the American Bar Foundation, membership in which is limited to one-third of one percent of the lawyers in America
  • For more than 15 years, Law & Politics and Milwaukee Magazine has selected Greg for inclusion in Wisconsin Super Lawyers, a distinction limited to the top 5% of Wisconsin attorneys.
  • Named one of “Milwaukee’s Leading Lawyers,” in 2015, 2016, and 2017 by M Magazine in Litigation. Only 2–5% of the top ranked attorneys published by for each category were recognized

    Articles/Presentations

  • Speaker, Milwaukee Chapter of the Society of Financial Service Professionals, “Dealing with Possible Elder Financial Abuse and its Potential Legal Ramifications” (Milwaukee, WI, March 2020)
  • Author, "Wisconsin Supreme Court Determines Statutory Medical Malpractice Cap Constitutional" Meritas Healthcare Newsletter (January 2020)
  • Co-Author “What Happens if My Business Can’t Perform Its Contract Due to the Coronavirus?,” website article (March 19, 2020)
  • Author, "A Trustee’s Duty of Loyalty in Wisconsin," website article (July 31, 2018)
  • Author, "Mental Capacity Issues in Estate Planning Litigation," website article (March 30, 2018)
  • Speaker, O’Neil, Cannon, Hollman, DeJong & Laing, Hot Legal Topics for Small Firms & Solo Practitioners seminar, “Commercial Arbitration: Arbitration in the United States and Abroad” (Milwaukee, WI, October 2015)
  • Speaker, O’Neil, Cannon, Hollman, DeJong & Laing, Hot Ethics Topics for In-House Counsel seminar, “E-Discovery: The New Wisconsin Rules of Civil Procedure and Some Ethical Considerations for Managing Electronically Stored Information” (Milwaukee, WI, December 2010)
  • Speaker, State Bar of Wisconsin and Corporate Practice Institute, Inc., “Legal Ethics: A Review and Update, Including Emerging Issues” (Milwaukee, WI, December 2010)

    Community Involvement

  • Board of Directors–Executive Committee, Secretary, Revitalize Milwaukee
  • Milwaukee Justice Center, Pro Bono Volunteer
  • Marquette University Law School, Former Member Alumni Association Board of Directors
  • University of Wisconsin–Whitewater, Former Member Dean’s Advisory Board
  • University of Wisconsin–Whitewater, Former Protégé–Mentor
  • Various school and church committees

    Education

  • Marquette University Law School (J.D.)
  • UW Whitewater (B.A., magna cum laude)

Practice Areas Explained

Gregory W. "Greg" Lyons's Areas of Legal Practice

Each practice area below reflects the types of cases Gregory W. "Greg" Lyons handles, with a practical overview of what that area of law involves and how it may apply to your situation in Milwaukee.

Business & Corporate Law in Milwaukee

Business attorneys advise founders and growing companies on entity formation, contracts, financing, M&A, and dispute resolution.

Gregory W. "Greg" Lyons is one of 497,491 business attorneys indexed nationally. Browse business attorneys in Wisconsin →

Civil Litigation in Milwaukee

Civil litigation attorneys for breach of contract, business disputes, civil rights, and class action lawsuits.

Gregory W. "Greg" Lyons is one of 450,751 litigation attorneys indexed nationally. Browse litigation attorneys in Wisconsin →

Insurance Law in Milwaukee

Insurance attorneys for coverage disputes, bad faith claims, denied claims, and policy disputes.

Gregory W. "Greg" Lyons is one of 120,903 insurance attorneys indexed nationally. Browse insurance attorneys in Wisconsin →

Jurisdictional Context

Why Local Counsel Matters in Milwaukee

Practicing law in Wisconsin. Legal matters in Wisconsin are governed by state-specific rules of civil and criminal procedure, statutes of limitations, and substantive law. Cases originating in Milwaukee are typically filed in the local municipal court or the appropriate Wisconsin state district court, depending on subject matter and amount in controversy. An attorney licensed in Wisconsin brings working knowledge of local procedural deadlines, judicial practices in this venue, and the substantive law that applies to cases brought here. Out-of-state attorneys generally cannot represent clients in Wisconsin courts without local counsel or pro hac vice admission.

Milwaukee Courts and Legal Process

Choosing a Milwaukee-based attorney means your counsel already knows the local docketing timelines, preferred filing formats, and how individual judges typically rule on procedural motions — details that only come from practicing in this jurisdiction day after day. That local familiarity can translate to better strategy, faster filings, and fewer costly surprises.

Looking for additional Wisconsin attorneys? Browse all attorneys in Milwaukee or all attorneys in Wisconsin.

Frequently Asked

Common Questions About Gregory W. "Greg" Lyons

Where is Gregory W. "Greg" Lyons's law office located?
Gregory W. "Greg" Lyons's law practice is located in Milwaukee, Wisconsin. The firm is O'Neil, Cannon, Hollman, DeJong & Laing SC. You can contact the office directly through this profile page.
What practice areas does Gregory W. "Greg" Lyons handle?
Gregory W. "Greg" Lyons focuses on business, litigation, insurance. Each practice area listed reflects experience handling cases of that type in Wisconsin.
Where did Gregory W. "Greg" Lyons go to law school?
Gregory W. "Greg" Lyons earned their education at (J.D., 1988).
How can I contact Gregory W. "Greg" Lyons for a consultation?
You can contact Gregory W. "Greg" Lyons directly through this profile page. Click "Ask the Attorney" to submit a question, or "Schedule a Consultation" to book a meeting. Most claimed-profile attorneys respond within one business day.
What awards or recognition has Gregory W. "Greg" Lyons received?
Gregory W. "Greg" Lyons's notable recognition includes: Best Lawyers in America — Commercial Litigation; Best Lawyers in America — Litigation - Insurance; Best Lawyers in America — Additional Areas of Practice:; Best Lawyers in America — Appellate Practice; Best Lawyers in America — Arbitration.

Professional Profile

Why Clients in Milwaukee Choose Gregory W. "Greg" Lyons

Selecting an attorney is one of the most consequential decisions you can make when a legal matter arises. Below are the core qualities that distinguish Gregory W. "Greg" Lyons's practice in the field of business, litigation, and insurance.

Broad Practice Area Coverage

Covering business, litigation, and insurance, Gregory W. "Greg" Lyons can address the full spectrum of a client's legal needs without requiring referrals to separate specialists for each issue.

Local Presence in Milwaukee

A Milwaukee-based practice means Gregory W. "Greg" Lyons attends hearings in the same courthouses, knows the local clerks, and understands the unwritten scheduling norms that affect every case filed here.

Case Types

Common Legal Issues Gregory W. "Greg" Lyons Handles in Milwaukee

Below is a representative sample of the types of matters Gregory W. "Greg" Lyons has experience with under Wisconsin law. If your situation involves one of these case categories, this attorney may be well positioned to help you understand your options.

Business formation and structure
Business
Contract drafting and review
Business
Partnership disputes
Business
Merger and acquisition support
Business

This list is illustrative, not exhaustive. Contact Gregory W. "Greg" Lyons directly to discuss the specifics of your situation.

Search Reference

How People Find Gregory W. "Greg" Lyons Online

Prospective clients searching for legal help in Milwaukee commonly use a combination of the attorney's name and their specific legal need. The following search terms frequently lead people to this profile and to attorneys like Gregory W. "Greg" Lyons.

Gregory W. "Greg" Lyons attorney Gregory W. "Greg" Lyons lawyer Gregory W. "Greg" Lyons Milwaukee Gregory W. "Greg" Lyons Wisconsin Gregory W. "Greg" Lyons reviews Gregory W. "Greg" Lyons contact O'Neil, Cannon, Hollman, DeJong & Laing SC law firm business attorney in Milwaukee business lawyer Milwaukee best business attorney Milwaukee top rated business lawyer near me business attorney Wisconsin find a lawyer near me how to hire an attorney

If any of the above matches what you searched for, you've found the right profile. Use the contact options at the top of this page to get in touch with Gregory W. "Greg" Lyons directly.

Gregory W. "Greg" Lyons's Practice Areas & Specializations

Education & Law School Background

J.D.
Marquette University
- 1988

Awards & Professional Honors

Best Lawyers in America — Commercial Litigation
- 2026
Best Lawyers in America — Litigation - Insurance
- 2026
Best Lawyers in America — Additional Areas of Practice:
- 2026
Best Lawyers in America — Appellate Practice
- 2026
Best Lawyers in America — Arbitration
- 2026
Best Lawyers in America — Bet-the-Company Litigation
- 2026
Best Lawyers in America — Ethics and Professional Responsibility Law
- 2026
Best Lawyers in America — Litigation - Banking and Finance
- 2026
Best Lawyers in America — Litigation - Construction
- 2026
Best Lawyers in America — Litigation - Land Use and Zoning
- 2026
Best Lawyers in America — Litigation - Mergers and Acquisitions
- 2026
Best Lawyers in America — Litigation - Real Estate
- 2026
Best Lawyers in America — Litigation - Trusts and Estates
- 2026
Best Lawyers in America — Mass Tort Litigation
- 2026
Best Lawyers in America — Personal Injury Litigation
- 2026
Best Lawyers in America — Product Liability Litigation
- 2026
Best Lawyers in America — Product Liability Litigation - Defendants
- 2026
Best Lawyers in America — Special Focus:
- 2026
Best Lawyers in America — COVID-19
- 2026
Best Lawyers in America — Product Liability
- 2026
Best Lawyers in America — Awards:
- 2026
Best Lawyers in America — Named 2022 Best Lawyers “Lawyer of the Year” for Litigation–Insurance
- 2026
Best Lawyers in America — Named 2022 Attorney of the Year by Top 100 Registry
- 2026
Lawyer of the Year — Litigation - Insurance (Milwaukee)
- 2022

Bar Admissions & Licensed Jurisdictions

Wisconsin, State Bar of Wisconsin

Client Reviews & Ratings — Gregory W. "Greg" Lyons

These reviews belong to platform users; they do not constitute advertisement or promotion for the attorney. Opinions are published for informational purposes only.

No reviews yet.