Darnell earned his undergraduate degree from Austin Peay State University in 1962 before earning his law degree at Vanderbilt in 1965. He served in the U.S. Air Force as a captain and judge advocate general from 1966 to 1969 and then returned to Clarksville to practice law.
Darnell was elected to the Tennessee House of Representatives in 1970 to represent the 67th District. He served for two five-year terms and was then elected to the State Senate, where he rose to majority leader. He served in the state senate for 12 years.
In 1993, his former colleagues in the Tennessee General Assembly selected Darnell to serve as Tennessee’s secretary of state. He served in that position until 2009, when he retired.
In 2019, he endowed the Riley C. Darnell Legislative Intern Scholarship to Austin Peay State University.
Darnell is survived by his wife, Penny, and their five children.
His death was announced by Tre Hargett, who currently serves as Tennessee secretary of state. “I and our entire office send condolences to the family of former Tennessee Secretary of State Riley Darnell,” Hargett stated. “In addition to serving as secretary of state, he was a husband, father, veteran and member of the Tennessee General Assembly. Our state and nation are better for his service.”