The 2021 Lamar Hunt U.S. Open Cup was planned to be the 107th edition of the U.S. Open Cup, a knockout cup competition in American soccer. After the 2020 competition was suspended and ultimately canceled due to the COVID-19 pandemic, the United States Soccer Federation announced that qualification for the 2021 Open Cup would be canceled and all 100 teams that had qualified for that competition would be invited back. On February 8, 2021, the U.S. Soccer Federation backtracked and stated that only 24 teams would be allowed to participate in a new abbreviated tournament, with the exact qualification details still being determined.