Our Attorneys

Daniel N. Christus

Daniel N. Christus serves as counsel with Simpson Dattilo, LLC where he counsels clients related to intellectual property matters.  As a partner with two prominent Chicago law firms for nearly four decades prior to joining Simpson Dattilo, Mr. Christus represented clients in all aspects of intellectual property, with an emphasis on patent and trademark prosecution and litigation.  His clients have included U.S. and foreign manufacturers and distributors of medical devices, food products, electrical circuit protection devices, stamped metal products, premium bathroom and kitchen fixtures, hair and skin care products, marking implements, plumbing products, packaging and labelling products, and fine American and Italian wines and liquors.   

From 2006 to 2018, Mr. Christus practiced as a partner with a Chicago-based AmLaw 50 firm.  There, his practice expanded to meet the growing patent and trademark needs of new and existing domestic and international clients.

He represented those clients in over eighty contentious proceedings in various tribunals including in Federal District Courts, before arbitration panels, and in opposition and cancellation proceedings in the Trademark Trial and Appeal Board of the United States Patent and Trademark Office.   Mr. Christus successfully defended attempts to invalidate clients’ patents in litigation and arbitrations.  He worked with clients on “design-around” projects for their proposed new products to ensure that those products would not infringe existing patents, and then authored detailed non-infringement opinions for those products.  Mr. Christus authored and filed patent applications on those and many other products.  He also reviewed and provided clearance opinions for thousands of proposed trademarks, filed hundreds of United States trademark applications on behalf of his clients, and coordinated and arranged for the filing of corresponding foreign trademark applications.       

From 1984 to 2006, Mr. Christus was a partner with a Chicago intellectual property boutique and worked with his clients in connection with all of their intellectual property needs.  For example, Mr. Christus headed a team that worked with a major client to successfully “design around” a competitor’s U.S. and international patent portfolio comprising over 120 patents.  Mr. Christus was also a key member of a defense team in a 2002 patent litigation in Milwaukee, Wisconsin where the client was charged with infringement of several patents and faced a potential verdict that would have ended the client’s manufacture of the accused product and payment of over $130 million in damages to the plaintiff.  After a seven-day trial, the jury found in favor of the client.  The verdict was a complete victory for the client, who was able to continue its manufacture of the product and pay nothing in damages.  

Mr. Christus has presented seminars on intellectual property at the University of Wisconsin, before the American University in Washington, D.C., and before bar associations in Milwaukee, Wisconsin.  He was the president of the Hellenic Bar Association of Illinois in 1997-1998 and was a six-term member of the Parish Council of St. Andrew Greek Orthodox Church in Chicago.


  • Supreme Court of Illinois
  • U.S. Court of Appeals – Federal, 7th and 11th Circuits
  • U.S. District Court – N.D. and W.D. Illinois
  • U.S. Patent & Trademark Office


Mr. Christus is a graduate of the University of Wisconsin-Madison where he earned his Juris Doctor and a Bachelor of Science in Chemical Engineering.

Contact Matthew

Email: dan@simpsondattilo.com

Phone: (312) 416-1953 ext. 3

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