The Crossover Classic (branded as the Crossover Classic presented by Mammoth Sports Construction for sponsorship reasons) is an early-season college basketball tournament that first took place November 25–30, 2020, at the Sanford Pentagon in Sioux Falls, South Dakota.

The tournament was originally established in 2020, intending to be a de facto substitute for the Battle 4 Atlantis tournament following its cancellation due to the COVID-19 pandemic; organizers invited all of the teams that had been invited to participate that year, but due to withdrawals only two of the originally-invited teams participated. The tournament returned for 2021, this time as a four-team round robin event.

The Battle 4 Atlantis tournament in Nassau, Bahamas was cancelled due to logistical issues tied to the COVID-19 pandemic. In the wake of the decision, a representative of the event was contacted by one of the teams' coaches, suggesting that an event could be held at the Pentagon.^[1] Attempts were made to invite all of the teams who had originally been slated to compete at the 2020 edition of the Battle 4 Atlantis, with only Duke declining. South Dakota had among the highest rates of new COVID-19 cases per-capita nationwide, but the tournament and venue's association with the local Sanford Health system was stated by organizers as allowing them to "put together a plan to make this a safe environment for all the teams that have committed to playing here."^[1]

Creighton, Dayton, Ohio State, Texas A&M, and Utah dropped out of the tournament prior to the event. The day before the tournament was scheduled to begin, Wichita State withdrew due to a COVID-19 outbreak on the team, leaving only two of the originally-invited teams left.^[2] It was originally planning to admit a limited number of spectators per-game, but on November 23 it was announced that the tournament would be played behind closed doors with no spectators admitted.^[3]

The tournament returned for 2021, switching to a round-robin format with four invited teams.^[4]