Independent School League (Washington, D.C. area)

The Independent School League or ISL is a prep school athletic conference located in the Washington, D.C. metropolitan area of the United States. It was founded in 1985. Although the ISL sponsors only girls' sports, not all fifteen ISL schools are "all-girls" schools.

The ISL sponsors ten sports: basketball, cross country, field hockey, lacrosse, soccer, softball, swimming & diving, tennis, track & field, and volleyball. Most of these competitions are divided into two divisions, with yearly promotion and relegation between the two divisions.