*Leagues affiliated with American or Canadian sports leagues, or partaking in inter-league play with American or Canadian sports leagues are included as well. Baseball's scope of focus is broadened to include Latin America as well.
**Professional means that the players are paid, so some leagues that may be conceived as professional by many but are technically amateur are NOT included.

American Football
Major
National Football League
Independent
Hawaii Professional Football League
Stars Football League
United Football League

Arena Football
Major
Arena Football League
Women's
Canadian Lingerie Football League
Leather and Lace Football League
Lingerie Football League

Baseball
Major
Major League Baseball
AAA
International League
Mexican League
Pacific Coast League
AA
Eastern League
Southern League
Texas League
Advanced A
California League
Carolina League
Florida State League
A
Midwest League
South Atlantic League
Short-season A
New York-Penn League
Northwest League
Advanced Rookie
Appalachian League
Pioneer League
Rookie
Arizona League
Dominican Summer League
Gulf Coast League
Venezuelan Summer League
Affiliated Off-season
Arizona Fall League
Australian Baseball League
Dominican Professional Baseball League
Mexican Pacific League
Puerto Rico Baseball League
Venezuelan Professional Baseball League
Independent
American Association
Atlantic League
Canadian American Association
Frontier League
Gulf Coast Baseball League
North American League
Pecos League
Independent Off-season
Colombian Professional Baseball League
Nicaraguan Professional Baseball League
Veracruz Winter League

Basketball
Major
National Basketball Association
Minor
National Basketball Association Development League
Independent
American Basketball Association
Atlantic Coast Professional Basketball League
Continental Basketball League
Eastern Basketball Alliance
International Basketball League
National Basketball League of Canada
Premier Basketball League
Universal Basketball Association
United Basketball League
West Coast Professional Basketball League
World Basketball Association Exposure League
Independent Minor
Universal Basketball Association D-League
Women's
Women's National Basketball Association

Canadian Football
Major
Canadian Football League

Ice Hockey
Major
National Hockey League
AAA
American Hockey League
AA
Central Hockey League
ECHL
A
Federal Hockey League
Ligue Nord-Américaine de Hockey
Southern Professional Hockey League

Indoor Football
Major
Indoor Football League
Southern Indoor Football League
Independent
Continental Indoor Football League
Ultimate Indoor Football League
Western Indoor Football Association

Indoor Lacrosse
Major
Canadian Lacrosse League
National Lacrosse League
North American Lacrosse League

Indoor Soccer
Major
Canadian Major Indoor Soccer League
Major Indoor Soccer League
Mexican Indoor Football League
Professional Arena Soccer League

Lacrosse
Major
Major League Lacrosse

Roller Hockey
Major
Major League Roller Hockey

Softball
Women's
National Pro Fastpitch

Soccer
Major
Major League Soccer
Reserve
Major League Soccer Reserve League
Division 2
North American Soccer League
Division 3
Canadian Soccer League
United Soccer Leagues Professional Division
Women's
Women's Professional Soccer

Team Boxing
Major
World Series of Boxing

Team Tennis
Coed
World TeamTennis