Isaac Newton Blackford (November 6, 1786 – December 31, 1859) was the second Chief Justice of the Indiana Supreme Court, the court's longest serving Justice, and among the longest serving jurists in the history of the United States. He wrote an eight-volume work entitled "Blackford's Reports" recording all the early decisions of the court. The books became a staple legal source among Indiana's lawyers and received national and international acclaim for its style, accuracy, quality, and concision in dealing with common law. As a jurist, Blackford was the most influential ever to serve on Indiana's courts, according to former Chief Justice of Indiana Randall Shepard. He was nicknamed the "Indiana Blackstone" because of a comment made by Washington Irving regarding the popularity of Blackford's books. During his lifetime he was nationally renowned as one of the most prominent jurists in the United States.