Giải quần vợt Mỹ Mở rộng 2018
Hạt giống đơn > Đơn nữ

| Hạt giống | Xếp hạng | Tay vợt | Điểm trước thi đấu | Điểm bảo vệ | Điểm thắng | Điểm sau thi đấu | Thực trạng |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 1 | 1 |  Simona Halep | 8,061 | 10 | 10 | 8,061 | First round lost to  Kaia Kanepi |
| 2 | 2 |  Caroline Wozniacki | 5,975 | 70 | 70 | 5,975 | Second round lost to  Lesia Tsurenko |
| 3 | 3 |  Sloane Stephens | 5,482 | 2,000 | 430 | 3,912 | Quarterfinals lost to  Anastasija Sevastova [19] |
| 4 | 4 |  Angelique Kerber | 5,305 | 10 | 130 | 5,425 | Third round lost to  Dominika Cibulková [29] |
| 5 | 5 |  Petra Kvitová | 4,885 | 430 | 130 | 4,585 | Third round lost to  Aryna Sabalenka [26] |
| 6 | 6 |  Caroline Garcia | 4,725 | 130 | 130 | 4,725 | Third round lost to  Carla Suárez Navarro [30] |
| 7 | 7 |  Elina Svitolina | 4,555 | 240 | 240 | 4,555 | Fourth round lost to  Anastasija Sevastova [19] |
| 8 | 8 |  Karolína Plíšková | 4,105 | 430 | 430 | 4,105 | Quarterfinals lost to  Serena Williams [17] |
| 9 | 9 |  Julia Görges | 3,900 | 240 | 70 | 3,730 | Second round lost to  Ekaterina Makarova |
| 10 | 10 |  Jeļena Ostapenko | 3,787 | 130 | 130 | 3,787 | Third round lost to  Maria Sharapova [22] |
| 11 | 11 |  Daria Kasatkina | 3,525 | 240 | 70 | 3,355 | Second round lost to  Aliaksandra Sasnovich |
| 12 | 12 |  Garbiñe Muguruza | 3,500 | 240 | 70 | 3,330 | Second round lost to  Karolína Muchová [Q] |
| 13 | 13 |  Kiki Bertens | 3,260 | 10 | 130 | 3,380 | Third round lost to  Markéta Vondroušová |
| 14 | 14 |  Madison Keys | 3,212 | 1,300 | 780 | 2,692 | Semifinals lost to  Naomi Osaka [20] |
| 15 | 15 |  Elise Mertens | 2,940 | 10 | 240 | 3,170 | Fourth round lost to  Sloane Stephens [3] |
| 16 | 16 |  Venus Williams | 2,841 | 780 | 130 | 2,191 | Third round lost to  Serena Williams [17] |
| 17† | 26 |  Serena Williams | 1,676 | 0 | 1,300 | 2,976 | Runner-up, lost to  Naomi Osaka [20] |
| 18 | 17 |  Ashleigh Barty | 2,740 | 130 | 240 | 2,850 | Fourth round lost to  Karolína Plíšková [8] |
| 19 | 18 |  Anastasija Sevastova | 2,250 | 430 | 780 | 2,600 | Semifinals lost to  Serena Williams [17] |
| 20 | 19 |  Naomi Osaka | 2,245 | 130 | 2,000 | 4,115 | Champion, defeated  Serena Williams [17] |
| 21 | 21 |  Mihaela Buzărnescu | 2,068 | 40 | 0 | 2,028 | Withdrew due to right ankle injury |
| 22 | 22 |  Maria Sharapova | 2,003 | 240 | 240 | 2,003 | Fourth round lost to  Carla Suárez Navarro [30] |
| 23 | 23 |  Barbora Strýcová | 1,930 | 70 | 130 | 1,990 | Third round lost to  Elise Mertens [15] |
| 24 | 25 |  CoCo Vandeweghe | 1,878 | 780 | 10 | 1,108 | First round lost to  Kirsten Flipkens |
| 25 | 32 |  Daria Gavrilova | 1,435 | 70 | 70 | 1,435 | Second round lost to  Victoria Azarenka [WC] |
| 26 | 20 |  Aryna Sabalenka | 2,140 | (60)‡ | 240 | 2,320 | Fourth round lost to  Naomi Osaka [20] |
| 27 | 28 |  Anastasia Pavlyuchenkova | 1,585 | 10 | 10 | 1,585 | First round lost to  Rebecca Peterson |
| 28 | 27 |  Anett Kontaveit | 1,665 | 10 | 10 | 1,665 | First round lost to  Kateřina Siniaková |
| 29 | 35 |  Dominika Cibulková | 1,390 | 70 | 240 | 1,560 | Fourth round lost to  Madison Keys [14] |
| 30 | 24 |  Carla Suárez Navarro | 1,879 | 240 | 430 | 2,069 | Quarterfinals lost to  Madison Keys [14] |
| 31 | 29 |  Magdaléna Rybáriková | 1,540 | 130 | 10 | 1,420 | First round lost to  Wang Qiang |
| 32 | 30 |  Maria Sakkari | 1,514 | 130 | 70 | 1,454 | Second round lost to  Sofia Kenin |
† Serena Williams was ranked 26 on the day when seeds were announced. Nevertheless she was deemed a special case and seeded 17th by the organizers because she missed a significant portion of the last 12-month period due to pregnancy and maternity.

‡ The player did not qualify for the tournament in 2017. Accordingly, points for her 16th best result are deducted instead.