The Prince William Swim League (PWSL) was founded in 1972 to sponsor swimming in and among the communities in Prince William County. All PWSL policies and procedures focus on providing a safe, fun, fair, and athletically challenging program for all swimmers while developing the principles of good sportsmanship, advanced swimming skills, and teamwork.

Teams are grouped in divisions based on factors such as team size (number of swimmers), team depth (distribution of swimmers across the age ranges), and the speed of the swimmers. The alignment of teams is done with the intent of maximizing competitiveness within the league.

The 7 divisions and 23 teams making up the PWSL for the 2007 season are listed here