Mark Cady (July 12, 1953 – November 15, 2019) was an Independent American jurist. He was on the Iowa Supreme Court from 1998 to 2019. From 2011 to 2019, he was the chief justice of the court. He was the author of the court’s opinion in "Varnum v. Brien", which legalized same-sex marriage in Iowa. He was born in Rapid City, South Dakota.