National Football League
- NFL.comNational Football League homepage - includes scores, rosters, rules, and other league information.
- NFL Players AssociationCollective bargaining representative for all current NFL players.
- Over The CapThis site tracks NFL player contracts and salary cap information. The information is unofficial and the site is not affiliated with the NFL, NFLPA, or any individual teams.
- Getting to the 2011-2020 National Football League Collective Bargaining AgreementPaper includes a summary of the history of past NFL CBAs.
National Hockey League
- NHL.comNational Hockey League homepage - includes scores, rosters, rules, and other league information.
- NHLPACollective bargaining representative for all current NHL players.
- Pro Hockey Players AssociationCollective bargaining representative for professional hockey players in the AHL and ECHL, the NHL's minor league affiliates.
Major League Baseball
- MLB.comMajor League Baseball homepage - includes scores, rosters, rules, and other league information.
- Major League Baseball Players AssociationCollective bargaining representative for all current MLB players.
- Cot's Baseball ContractsThis site tracks Major League Baseball contracts, signing bonuses, service time and franchise values. The information is unofficial and has been collected from various published reports and sources in and around the game.
- Cot's CBA HistorySummary of the collective bargaining history between MLB and the MLBPA
Womens National Basketball Association
- WNBA.comWomens National Basketball Association homepage - includes scores, rosters, rules, and other league information.
- Womens National Basketball Players AssociationCollective bargaining representative for all current WNBA players
- WNBA Salaries - The SummittThis site tracks WNBA player contracts and salary information. The information is unofficial.
Other Professional Sports Associations
- Jockeys GuildLabor union for jockeys.
- Professional Fighters AssociationAssociation seeking to represent professional MMA fighters.
- Professional Tennis Players Association (PTPA)Formally founded in 2021 as a not-for-profit corporation that "addresses player challenges and influences fair change within the business of professional tennis."
National Basketball Association
- NBA.comNational Basketball Association homepage - includes scores, rosters, rules, and other league information
- National Basketball Players AssociationCollective bargaining representative for all current NBA players.
- NBA Contracts Summary - Basketball ReferenceThis site tracks NBA player contracts and salary cap information. The information is unofficial.
Major League Soccer
- MLS SoccerMajor League Soccer homepage - includes scores, rosters, rules, and other league information.
- MLS Players AssociationCollective bargaining representative for all current MLS players.
- MLS Salary GuideCurrent salary information for all MLS players provided by the MLS Players Association.
Amateur/National Team Sports Associations
- US Men's National Soccer Team Player AssociationCollective bargaining representative for all US Men's National Soccer Team players.
- National College Players AssociationThe NCPA's mission is "to protect future, current, and former college athletes."
- College Athletes Players AssociationOrganization which sought to unionize Northwestern football players.