Mark W. Guest


Following his 2009 admission to the Illinois Bar, Mark accepted a position with Prairie State Legal Services, a not-for-profit law firm dedicated to providing free legal aid to low-income individuals in northern and central Illinois. He began in their Rock Island Office, where he assisted individuals in the counties of Rock Island, Henry, Mercer, and Cambridge with any and all civil, legal problems that impacted their basic human needs. He represented clients in matters that spanned a broad range of practice areas, including landlord/tenant law, bankruptcy, foreclosures, family law, nursing homes, tort law, social security disability, supplemental security income, veterans’ affairs benefits, domestic violence, and the Fair Housing Act.

Recognized by the organization for his commitment to the cause, Mark was promoted to Project Manager of the Lake County Office’s Homeless Project. As head of the initiative, he balanced a heavy caseload with his project management responsibilities. He focused a large portion of his practice on litigating cases geared toward eliminating the legal barriers preventing his homeless clients from obtaining housing and improving their circumstances. Looking back, Mark notes that while demanding, his position at Prairie State Legal Services taught him how to make do with limited resources and provided him with a tremendous amount of practice experience, both in and out of the courtroom.

After four and a half years, Mark decided to try his hand in private practice, and took a position at a boutique law firm that focused on community association law. Mark represented clients at the trial and appellate levels in both state and federal court in disputes involving breach of fiduciary duty, insurance coverage, real estate development, construction defects, shareholder derivative suites, fair housing, tortious interference with economic opportunity, personal injury, premises liability, bankruptcy, and foreclosure.

Since joining Patton & Ryan, Mark has focused his practice on product liability, construction defect litigation and bad faith insurance coverage matters. Recently, Mark was a trial team member on a complex Colorado construction defect case in which more than 20 plaintiffs leveled multiple claims against our client. After months of hard work and preparation, the Patton & Ryan team obtained a favorable jury verdict that was well under our client’s last settlement offer.


  • University of Notre Dame, BA, 2005, Cum Laude
  • Saint Louis University, JD, 2009, Notes and Comments Editor of the Saint Louis University Law Journal, 2007-2008 academic year.


  • Illinois, 2009
  • U.S District Court of the North District of Illinois, 2013

In the Community

  • PADS Lake County, Emergency Homeless Shelter, Board of Directors
  • Founder of the PADS Lake County Young Professionals Advisory Board