2021–2024 NCAA conference realignment

Beginning in the 2021–22 academic year, extensive changes occurred in NCAA conference membership, primarily at the Division I level.

Most of these changes have involved conferences in the Football Bowl Subdivision (FBS) of Division I. Of the 10 FBS conferences that existed at the start of the realignment cycle, only the Mid-American Conference and Mountain West Conference have seen no change in their core membership. The most notable change is the effective demise of the Pac-12 Conference, which has so far seen 10 of its 12 members leave for other conferences—four each to the Big Ten Conference and Big 12 Conference, and two to the Atlantic Coast Conference.

The Division I Football Championship Subdivision (FCS) also saw significant changes, most notably the beginning of football sponsorship by the Atlantic Sun Conference (ASUN); the return of football by the Western Athletic Conference, which previously sponsored football at the FBS level until the end of the 2012 season; and two football-only conference mergers, one involving the ASUN and WAC and the other involving the Big South Conference and Ohio Valley Conference (OVC).

Other sports saw significant change:

• In men's ice hockey, the Central Collegiate Hockey Association (CCHA) was reestablished by seven members of the men's Western Collegiate Hockey Association (WCHA), which led to the WCHA disbanding its men's league and becoming a women's-only conference. Also, the men-only Atlantic Hockey Association and the women-only College Hockey America announced they would merge into a single conference after the 2023–24 season.
• In men's soccer, the Sun Belt Conference reinstated the sport, ultimately leading to both Conference USA (CUSA) and the Mid-American Conference dropping the sport, and the OVC also added the sport.
• The Atlantic 10 Conference launched a men's lacrosse league, leading to the Northeast Conference (NEC) and the Southern Conference dropping the sport. However, the NEC later announced it would reinstate men's lacrosse in 2024–25.
• The NEC became the second D-I all-sports conference to sponsor men's volleyball.
• The West Coast Conference and the Big West Conference added men's water polo, which led to the demise of the men's side of the water polo-only Golden Coast Conference.
• Several all-sports conferences underwent single-sport mergers:
  • The OVC merged its men's tennis league into the Horizon League.
  • The Mid-Eastern Athletic Conference merged its baseball league into the NEC.
  • The Southland Bowling League was absorbed by CUSA.
  • The ASUN added men's and women's swimming & diving, effectively taking over the aquatics side of the Coastal Collegiate Sports Association and leaving the latter a beach volleyball-only conference.