Atty. Diane M. Johnsen
Diane M. Johnsen is a top attorney recognized by Best Lawyers in the practice area(s) of Appellate Practice, Commercial Litigation and Environmental Law.
Profile Summary
About Diane M. Johnsen at a glance
Diane M. Johnsen is a business, litigation, environmental, and appellate attorney based in Phoenix, Arizona, practicing at Perkins Coie LLP. Educated at Duke University (J.D., 2016). Recognitions include Lawyer of the Year — Appellate Practice (Phoenix) (2026), Best Lawyers in America — Appellate Practice (2026), and Best Lawyers in America — Commercial Litigation (2026). Serands clients in Phoenix, AZ and the surrounding metropolitan area.
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About
- Diane M. Johnsen is a top attorney recognized by Best Lawyers in the practice area(s) of Appellate Practice, Commercial Litigation and Environmental Law
- Diane M., who practices law in Phoenix, Arizona, has been recognized since 2005
- This recognition is based on an exhaustive peer-review survey, reflecting the high esteem in which Diane M. is held by other top lawyers in the same geographic and legal practice area
Practice Areas Explained
Diane M. Johnsen's Areas of Practice
Each practice area below reflects the types of cases Diane M. Johnsen handles, with a brief overview of what that area of law covers.
Business attorneys advise founders and growing companies on entity formation, contracts, financing, M&A, and dispute resolution.
Diane M. Johnsen is one of 501,317 business attorneys indexed nationally. Browse business attorneys in Arizona →
Civil litigation attorneys for breach of contract, business disputes, civil rights, and class action lawsuits.
Diane M. Johnsen is one of 454,532 litigation attorneys indexed nationally. Browse litigation attorneys in Arizona →
Environmental attorneys for regulatory compliance, contamination, land use, and natural resource law.
Diane M. Johnsen is one of 56,434 environmental attorneys indexed nationally. Browse environmental attorneys in Arizona →
Appellate attorneys for civil and criminal appeals at state and federal court.
Diane M. Johnsen is one of 86,319 appellate attorneys indexed nationally. Browse appellate attorneys in Arizona →
Jurisdictional Context
Why local counsel matters in Arizona
Practicing law in Arizona. Legal matters in Arizona are governed by state-specific rules of civil and criminal procedure, statutes of limitations, and substantive law. Cases originating in Phoenix are typically filed in the local municipal court or the appropriate Arizona state district court, depending on subject matter and amount in controversy. An attorney licensed in Arizona 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 Arizona courts without local counsel or pro hac vice admission.
Looking for additional Arizona attorneys? Browse all attorneys in Phoenix or all attorneys in Arizona.
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