The Colonial States Athletic Conference (CSAC) was an NCAA Division III collegiate athletic conference in the Mid-Atlantic United States that existed from 1992 to 2023.

[5] The conference added its 10th member on July 1, 2019,[6] and its 11th on the same day in 2020,[7] but was reduced to 10 members when on June 18, 2021, Centenary University published its move to Atlantic East, starting July 1 that year, but its lacrosse teams would start competing in their new conference's 2022 season.

[8] On December 19, 2022, the United East Conference and the Colonial States Athletic Conference announced their intent to merge beginning with the 2023–24 academic year.

The conference officially ceased to exist when its ten remaining members were absorbed by the United East Conference on July 1, 2023.

The CSAC had ten final full members, all were private schools: The CSAC had nine affiliate members when it dissolved:[14] The CSAC had 12 former full members, all were private schools: The CSAC had seven former affiliate members, four were private and three were public schools: