This article features a listing of the top-level professional minor league sports teams based in the United States that are typically the second tier of professional sports under the major professional leagues. The minor leagues listed below also include teams outside the United States, with seven in Canada (one in the NBA G League and six in the American Hockey League) and one in Mexico (NBA G League).
Triple-A minor league baseball has two leagues, the International League and Pacific Coast League, both affiliated with Major League Baseball. Basketball and ice hockey each have one affiliated minor league, the NBA G League and American Hockey League, respectively. The USL Championship (USLC) is a Division II league below Major League Soccer as designated by the United States Soccer Federation that governs the various soccer leagues, although some MLS teams are affiliated with clubs from outside the second tier for development purposes. However, most MLS clubs now field their reserve sides in MLS Next Pro, a third-level league that launched in 2022, and the only MLS club that has not announced plans to field a Next Pro side in 2023 is CF Montréal. There are no affiliated minor leagues for AmericanorCanadian football as most of its recruiting is done through college football, and minor football leagues do not historically have long lifespans before folding,. Currently there is one existing high level spring league: the United Football League, formed from the merger of the USFL and the XFL.
Teams that will join a league for a future season are indicated in italics.
