Attorneys of Onder Law - St. Louis Personal Injury Attorneys
Derek P. Sieck - St. Louis Lawyer

Derek P. Sieck

Pharmaceutical & Medical Products Litigation, Products Liability, Premises Liability, Motor Vehicle Accidents, Workers' Compensation

Email Address:sieck@onderlaw.com

Derek Sieck joined the Onder Law Firm as a clerk in 2014, and has been an attorney with the firm since graduating law school and passing the bar in 2017.

At the Onder Law Firm, Derek primarily handles pharmaceutical cases, general product liability matters, auto and trucking accidents, premise liability, and workers compensation cases.

Derek graduated with a Bachelor of Business Administration in Finance from the Tippie College of Business at the University of Iowa, in 2014. At the University of Iowa, Derek served as the Treasurer of Phi Alpha Delta Pre-Law Fraternity.

Derek completed his education at Saint Louis University School of Law in 2017. At St. Louis University, Derek used his business background to earn a concentration in Entrepreneurship Law. While working in the Entrepreneurship and Community Development Clinic in law school, he worked with a number of St. Louis area entrepreneurs with trademark and small business issues. He also earned a concentration in Criminal Litigation skills.

Derek is a member of the Missouri Association of Trial Attorneys and the Bar Association of Metropolitan St. Louis.

Derek is admitted to practice law in Missouri and Illinois.

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Onder Law holds the highest possible peer review rating from Martindale-Hubbell

Onder Law holds the highest possible peer review rating from Martindale-Hubbell

Million Dollar Advocates Forum

We have been recognized by the Million Dollar Advocates Foum for securing million dollar settlements on behalf of our clients. Fewer than 1% of all attorneys receive this recgonition.

Multi-Million Dollar Advocates Forum

We have been recognized by the Million Dollar Advocates Foum for securing multi-million dollar settlements on behalf of our clients. Fewer than 1% of all attorneys receive this recgonition.

Super Lawyers

The attorneys of Onder Law have been recognized as Super Lawyers

Multi-Million Dollar Advocates Forum

We have been nominated as one of the Best Attorneys in America - The Most Qualified Attorneys in Our Country by Rue Ratings

Member National Trial Lawyers Association

The attorneys of Onder Law are proud members of the National Trial Lawyers Association


Onder Law handles mass tort claims that are filed in federal courts nationwide. Attorneys at Onder Law are licensed only in Missouri, Illinois and Kansas; however our attorneys have handled cases nationwide* including in: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin and Wyoming.

Attorneys at Onder Law have represented clients in federal multi-district litigation in the following cities*: Atlanta, GA, Austin, TX, Baltimore, MD, Birmingham, AL, Boston, MA, Buffalo, NY, Charlotte, NC, Chicago, IL, Cincinnati, OH, Cleveland, OH, Columbus, OH, Dallas, TX, Denver, CO, Detroit, MI, Fresno, CA, Hartford, CT, Honolulu, HI, Houston, TX, Indianapolis, IN, Jacksonville, FL, Kansas City, MO, Las Vegas, NV, Los Angeles, CA, Louisville, KY, Memphis, TN, Miami, FL, Milwaukee, WI, Minneapolis, MN, Nashville, TN, New Orleans, LA, New York, NY, Oklahoma City, OK, Orlando, FL, Philadelphia, PA, Phoenix, AZ, Pittsburgh, PA, Portland, OR, Providence, RI, Raleigh, NC, Richmond, VA, Riverside, CA, Rochester, NY, Sacramento, CA, Salt Lake City, UT, San Antonio, TX, San Diego, CA San Francisco, CA, San Jose, CA, Seattle, WA, St. Louis, MO, Tampa, FL, Tucson, AZ, Tulsa, OK, Virginia Beach, VA and Washington, DC.

* In order to represent clients in states where the attorneys are not licensed, they must be granted admission pro hac vice or associate with local counsel.