Dunnings was born to lawyer and activist Stuart John Dunnings, Jr., and Janet Taylor Dunnings. He has two siblings; Shauna, who is a judge, and Steven, who is also a lawyer. Dunnings married Cynthia Dunnings in 1977. She filed for divorce in March 2016, following the charges made against him. Dunnings is a Democrat, and supported Barack Obama in the 2012 presidential election, with his personal website advertising said support.