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“Mark Arnold sets the gold standard for appellate practice in St. Louis.”

Missouri Supreme Court Justice Richard Teitelman


Mark strives to think outside the box and bring a fresh approach to each case. A litigator for 40 years, Mark is a seasoned debater who is energized by outsmarting his opposition.

Mark puts that competitive nature to work for his clients as he leads them through all phases of complex litigation. His practice focuses on antitrust, securities pension and welfare, toxic tort and product liability matters. He also handles appeals of major cases, interpreting complex federal statutes such as the Employee Retirement Income Security Act (ERISA) and the Racketeer Influenced and Corrupt Organizations Act (RICO).

In addition, Mark has extensive experience defending class actions.

“Mark Arnold sets the gold standard for appellate practice in St. Louis.”

Missouri Supreme Court Justice Richard Teitelman




  • The Best Lawyers in America, Appellate Practice, Commercial Litigation, 2001-2020
  • Best of CLE Spotlight, MoBar CLE, 2013
  • Missouri & Kansas Super Lawyers, Appellate, 2005-2019; Top 100, 2006; Top 50 St. Louis, 2005-2008
  • Missouri Bar Pro Bono Wall of Fame, 2012
  • The Missouri Bar, W. Oliver Rasch Award for Outstanding Article, 1996


  • J.D., Washington University in St. Louis School of Law
    • Order of the Coif
    • Washington University Law Quarterly, editor-in-chief
  • A.B., Oberlin College


  • Missouri
  • U.S. District Court, Northern District of Florida
  • U.S. District Court, Southern District of Illinois
  • U.S. District Court, Eastern District of Missouri
  • U.S. District Court, Western District of Missouri
  • U.S. Court of Appeals, First Circuit
  • U.S. Court of Appeals, Second Circuit
  • U.S. Court of Appeals, Third Circuit
  • U.S. Court of Appeals, Fourth Circuit
  • U.S. Court of Appeals, Fifth Circuit
  • U.S. Court of Appeals, Sixth Circuit
  • U.S. Court of Appeals, Seventh Circuit
  • U.S. Court of Appeals, Eighth Circuit
  • U.S. Court of Appeals, Ninth Circuit
  • U.S. Court of Appeals, Tenth Circuit
  • U.S. Court of Appeals, Eleventh Circuit
  • U.S. Court of Appeals, Federal Circuit
  • U.S. Court of Appeals, District of Columbia Circuit
  • U.S. Supreme Court

Professional Associations and Memberships

  • American Health Lawyers Association
  • American Law Institute, Life Member, 2014-present 
  • The Missouri Bar
  • Missouri Supreme Court, Civil Rules Committee; Ad Hoc Committee on Expert Discovery Rules
Featured Experience

Lender Prevails in Real Estate Class Action Suit

In a case in the U.S. District Court in Minnesota, Mark successfully defeated class certification for borrowers who alleged that the yield spread premium a lender paid a mortgage loan broker constituted illegal kickbacks and fee splitting under the Real Estate Settlement Practices Act (RESPA). In response to the defendants’ motion for reconsideration, the court reversed its earlier decision granting class certification and also granted the defendants’ motions for summary judgment on the liability issues, dismissing the claims with prejudice.

Additional Experience
  • Obtained outright reversal in Arkansas Court of Appeals of a million-dollar wrongful death judgment against a mall. A disgruntled ex-employee of a mall tenant killed the manager who had fired him. The court held that a landlord owes no duty to an employee of a tenant.
  • Successfully litigated patents and patent licensing for Bayer seed and other agricultural products.
  • Represented Farm Credit entities, including AgriBank, its predecessors and various production-credit associations, on general litigation matters.
  • Counseled lenders and buyers of farm products on enforceability of liens on agricultural products.
  • Obtained favorable ruling from Eighth Circuit Court of Appeals that affirmed lower court order denying remand and class certification in Class Action Fairness Act (CAFA) lawsuit against Chicago Title Insurance Co.
  • Defeated class certification in major consumer fraud case against national postsecondary education provider in Madison County, Illinois. Client was accused of violating Illinois Consumer Fraud Act and Private Business and Vocational Schools Act by not providing accurate information to prospective students for seven years. Plaintiffs' demand to settle case was more than $20 million. State appeals court denied class certification.
Case Studies
Conagra Brands

Workers from Conagra’s Russellville, Arkansas facility filed a wage-and-hour class and collective action lawsuit alleging violations of the Fair Labor Standards Act (FLSA) and the Arkansas Minimum Wage Act (AMWA), claiming that they should have been paid for time spent donning and doffing before and after shifts.

Thought Leadership
Blog Posts
Ag-Gag Law Update VIII
February 05, 2020
Meatless Meat Update VII
February 04, 2020
Proposition 12 Update
December 04, 2019
Meatless Meat Update VI
November 07, 2019
Meatless Meat Update IV
September 16, 2019
Minnesota Wine Update
July 30, 2019
Update: Meatless Meat
July 10, 2019
Udder Nonsense Update
July 03, 2019
Tennessee Alcohol Update
July 01, 2019
Iowa "Ag Gag" Law Update
April 24, 2019
Update: Ag-Gag Law
March 27, 2019
New Ag-Gag Law Update
March 12, 2019
Update on California Egg Law
January 17, 2019
The Latest Ag-Gag Law Update
January 16, 2019
The Latest Foie Gras Update
January 10, 2019
Meatless Meat Update
December 27, 2018
Dusky Frog Update III
November 28, 2018
Ag-Gag Update
November 13, 2018
Compelled Speech
November 05, 2018
Latest Dusky Frog Update
October 08, 2018
Gerawan Farms Update
September 28, 2018
Missouri Meatless Meat Statute
September 28, 2018
Foie Gras Update
June 20, 2018
Ag-Gag Law Update
June 07, 2018
California Egg Update
May 09, 2018
Dusky Frog Update
February 22, 2018
Ag-Gag Law Update
January 16, 2018
California Egg Update
December 19, 2017
Ag-Gag Law Update
October 12, 2017
Update of Markle
August 21, 2017
Update on Ag-Gag Laws
July 17, 2017
“Ag Gag” Laws
June 22, 2017
Update on Egg Suit
June 06, 2017
DeCoster Update
May 24, 2017
View all
Outside the Office

Mark is an avid Major League Baseball fan. He takes in as many St. Louis Cardinals games as he can.