The Southern Maryland Athletic Conference (SMAC) is a high school athletic league in Maryland, comprising the public secondary and high schools throughout Southern Maryland. The SMAC's membership consists of the following schools located in Calvert, Charles, and St. Mary's Counties:
St. Mary's Ryken High School was a member, and the only private Maryland school in a public league, but withdrew to join the Washington Catholic Athletic Conference (WCAC) in 2002.St. Charles High School became a member of SMAC in 2014.