"19 Somethin'" is a song written by David Lee and Chris DuBois and recorded by American country music singer Mark Wills. It was released in September 2002 as the first single from his Greatest Hits compilation album and spent six weeks at number one on the Hot Country Songs chart in early 2003. It reached number 23 on the Billboard Hot 100 and was the longer-lasting of Wills' two number one singles. It would go on to become the number 2 country song of the decade on Billboard's Hot Country Songs Chart.