Northern Garrett High School is a member of the Maryland Public Secondary School Athletic Association. The purpose of the MPSSAA is to promote and direct public high school interscholastic activities in order to assure that those activities contribute toward the entire educational program of the state of Maryland. The MPSSAA includes 186 public high schools, with over 100,000 student-athletes participating in 23 sports.
NHS belongs to the Appalachian Mountain Athletic Conference (AMAC). This conference includes schools from Maryland and West Virginia.