Dennis Owsley was born near Los Angeles, California, and earned a BA in chemistry and a PhD in organic chemistry from the University of California-Riverside. He and his late wife, Rosa, came to St. Louis in 1969. He has been a jazz album collector, aficionado and historian since 1958 and has seen most of the major artists in jazz in live performance. April 2018 marked his thirty-fifth anniversary presenting jazz on St. Louis Public Radio. He received the Millard S. Cohen Lifetime Achievement Award from St. Louis Public Radio in 2010 and was named a Jazz Hero of St. Louis by the Jazz Journalists Association. Jazz Unlimited won the Riverfront Times' Best of St. Louis Award in the "Best Jazz Show" category six times. He produced The Jazz History of St. Louis on St. Louis Public Radio, the second-longest music documentary in the history of radio, in 2014. In 2006, he published an award-winning book, City of Gabriels: The Jazz History of St. Louis, 1895-1973. In 2006, he was co-curator of the exhibit "The Jazz History of St. Louis."