The Sussex County Interscholastic League (SCIL) was a high school athletic conference located in Sussex County and Morris County, New Jersey. The league was formed in 1976 when a number of new high schools opened up in the previous year. The formation of the league was to promote athletics and to cut down on travel time and costs. The league operated under the auspices of the New Jersey State Interscholastic Athletic Association (NJSIAA), the statewide organization for high school sports.
In 2009, all SCIL member schools merged with other Morris County member schools to form the Northwest Jersey Athletic Conference, as a result of the realignment of conferences by the NJSIAA.
The SCIL offered a total of 21 sports (12 boys; 9 girls). In the sport of swimming, Wallkill Valley and Sussex Tech competed as one team known as Wall-Tech. Additionally, Sussex Tech participated in the SCIL in bowling.