Dennis is President and Chief Executive Officer of the law firm Clausen Miller P.C. where he oversees operations of the firm’s 12 offices in the United States and London. Based in Chicago, IL, Dennis and his team handle multiple lines of insurance coverage and defense matters focusing on complex first-party property insurance. 

Dennis’s philanthropic interests include having served on the Board of the American Cancer Society’s Chicago Division and spearheading the team that ran the Chicago marathon in 1998 in honor of a close friend who died of cancer. It is now a worldwide event that raises millions of dollars every year for cancer awareness, prevention and treatment. ACS estimates the 2024 Chicago Marathon event will cruise past the $2 million mark with 900+ runners. 

Dennis is a founding member of a 501(c)(3) charitable organization called T.U.F.T., which privately raises funds and provides grants to individuals fighting cancer. He is also a major supporter of St. Jude’s Children’s Hospital.