Atty. James G. "Jim" DeJong

Atty. James G. "Jim" DeJong

Jim’s practice focuses on representing privately held businesses and their owners on the wide variety of legal matters that may arise. This includes extensive experience with significant corporate transactions such as purchases and sales of businesses, complex contractual matters, and planning for business succession.

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Profile Summary

About James G. "Jim" DeJong at a glance

James G. "Jim" DeJong is a business, m&a, and securities 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., 1978). Recognitions include Best Lawyers in America — Corporate Law (2026), Best Lawyers in America — Mergers and Acquisitions Law (2026), and Best Lawyers in America — Securities / Capital Markets Law (2026). Serands clients in Milwaukee, WI and the surrounding metropolitan area.

Verified attorney profile · Updated June 2026

About

Jim’s practice focuses on representing privately held businesses and their owners on the wide variety of legal matters that may arise. This includes extensive experience with significant corporate transactions such as purchases and sales of businesses, complex contractual matters, and planning for business succession. In his practice, Jim works with clients across a wide range of industries, including fintech, manufacturing, distribution, and professional services. Jim has a unique perspective on the challenges of running a successful business having served as O’Neil Cannon’s President and Managing Shareholder for more than 25 years.

A cornerstone of Jim’s practice is building strong relationships with the clients’ owners and senior management. Jim’s experience has shown that effective legal counsel begins with a deep understanding of his clients’ businesses. This better positions him to provide tailored solutions that align with the clients’ goals and objectives. Jim and the law firm prioritize providing excellent legal work and exceptional client service delivered with efficiency, clarity, and practicality to minimize legal obstacles while maximizing opportunities for success.

Jim Assists Clients With

  • mergers, acquisitions, sales and recapitalizations of businesses;
  • shareholder agreements and operating agreements;
  • securities law matters, including private offerings of debt and equity securities;
  • restrictive covenants and nondisclosure agreements; and
  • day to day legal and business issues, governance, compliance, and operational matters.

    Jim’s Approach

    Jim has a proven track record of applying his decades of experience and common sense to help clients navigate legal challenges with confidence. Whether a client is planning a sale of a business, acquisition of another business, or seeking guidance on general legal matters, Jim is dedicated to delivering results-driven solutions that support long-term success.

    Awards/Distinctions

  • State Bar of Wisconsin
  • American Bar Association
  • Wisconsin Chapter of Association for Corporate Growth (ACG)

    Awards/Distinctions

  • Peer review rated as AV Preeminent®, the highest rating in the Martindale-Hubbell® Peer Review Rating™ System
  • Selected by his peers for inclusion in the Best Lawyers in America© (2010 - present) in the fields of corporate law, mergers and acquisitions, and securities/capital markets law
  • Selected for inclusion in the Wisconsin Super Lawyers list (2007- present)
  • Recipient of Carroll University’s MacAllister Distinguished Alumni Award (2019)

    Community Involvement

  • Served for nine years on the Board of Trustees of Carroll University, including three years as Board Chair.
  • Has been involved as a Board Member of the Milwaukee Repertory Theater and the Friends of Art of the Milwaukee Art Museum
  • Board Member, Thelma Sadoff Center for the Arts, Fond du Lac, Wisconsin
  • Ordained Elder, Presbyterian Church of United States of America

    Education

  • Marquette University Law School (J.D.)
  • Carroll University (B.S.)

Practice Areas Explained

James G. "Jim" DeJong's Areas of Practice

Each practice area below reflects the types of cases James G. "Jim" DeJong handles, with a brief overview of what that area of law covers.

Business & Corporate Law

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

James G. "Jim" DeJong is one of 501,317 business attorneys indexed nationally. Browse business attorneys in Wisconsin →

Mergers & Acquisitions

James G. "Jim" DeJong is one of 49,731 m&a attorneys indexed nationally. Browse m&a attorneys in Wisconsin →

Securities Law

James G. "Jim" DeJong is one of 64,529 securities attorneys indexed nationally. Browse securities attorneys in Wisconsin →

Jurisdictional Context

Why local counsel matters in Wisconsin

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 andnue, 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.

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

Frequently Asked

Common questions about James G. "Jim" DeJong

Where is James G. "Jim" DeJong's law office located?
James G. "Jim" DeJong'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 James G. "Jim" DeJong handle?
James G. "Jim" DeJong focuses on business, m&a, securities. Each practice area listed reflects experience handling cases of that type in Wisconsin.
Where did James G. "Jim" DeJong go to law school?
James G. "Jim" DeJong earned their education at (J.D., 1978).
How can I contact James G. "Jim" DeJong for a consultation?
You can contact James G. "Jim" DeJong 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 James G. "Jim" DeJong received?
James G. "Jim" DeJong's notable recognition includes: Best Lawyers in America — Corporate Law; Best Lawyers in America — Mergers and Acquisitions Law; Best Lawyers in America — Securities / Capital Markets Law; Best Lawyers in America — Special Focus:; Best Lawyers in America — Regulatory.

Education

J.D.
Marquette University
- 1978

Awards

Best Lawyers in America — Corporate Law
- 2026
Best Lawyers in America — Mergers and Acquisitions Law
- 2026
Best Lawyers in America — Securities / Capital Markets Law
- 2026
Best Lawyers in America — Special Focus:
- 2026
Best Lawyers in America — Regulatory
- 2026
Best Lawyers in America — Awards:
- 2026
Best Lawyers in America — Recipient of the 2019 P.E. MacAllister Distinguished Alumnus Award, presented by Carroll University
- 2026
Best Lawyers in America — Named one of “Milwaukee’s Leading Lawyers” in 2013, 2014, and 2015–Business, M Magazine
- 2026
Best Lawyers in America — Selected for inclusion in Wisconsin Super Lawyers in 2005–2023 Law & Politics and Milwaukee Magazine
- 2026
Best Lawyers in America — Recipient of an AV Preeminent™ 5.0 out of 5.0 rating by Martindale-Hubbell
- 2026

Bar Admissions

Wisconsin, State Bar of Wisconsin

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