| Champ: |  Ashlyn Krueger Robin Montgomery |
| Runner: | Reese Brantmeier Elvina Kalieva |
| Score: | 5–7, 6–3, [10–4] |
| Before Year: | 2019 |
See main article: 2021 US Open (tennis).
Kamilla Bartone and Oksana Selekhmeteva were the defending champions, having won the previous edition in 2019, however Bartone was no longer eligible to participate in junior events, whilst Selekhmeteva chose not to participate.
Ashlyn Krueger and Robin Montgomery won the title, defeating Reese Brantmeier and Elvina Kalieva in the final, 5–7, 6–3, [10–4].
All seeds received a bye into the second round.