The current WTA rankings are the usual criteria to decide seeding in the women's draw.
Williams, who has won the U.S. Open six times and will turn 37 next month, missed last year's tournament because of pregnancy.
In June, United States Tennis Association president Katrina Adams said the U.S. Open would revise seedings to take into account the effect of pregnancy on the current rankings of players.
Adams' comments came in the wake of widespread criticism of tennis officials after Serena was denied a seeding at this year's French Open, her first grand slam after returning to the sport.
Romanian Simona Halep is the top seed in the women's draw with defending champion Sloane Stephens at number three, ahead of Kerber, who won at Flushing Meadows in 2016.
There were no surprises on the men's side with world number one and defending champion Rafa Nadal named top seed, ahead of Roger Federer and Argentine Juan Martin del Porto in third.
Wimbledon champion Novak Djokovic, who heads to Flushing Meadows in arguably his best form since returning from a troublesome elbow injury, is seeded sixth, a place below big-serving South African Kevin Anderson.
John Isner is the highest-seeded American in the men's draw at number 11.
Australian No. 1 Ashleigh Barty is seeded 18 and Daria Gavrilova 25. The only seeded Australian on the men’s side of the draw is Nick Kyrgios at 30.
2018 US Open Women’s Singles Seeds
1. Simona Halep, Romania
2. Caroline Wozniacki, Denmark
3. Sloane Stephens, United States
4. Angelique Kerber, Germany
5. Petra Kvitova, Czech Republic
6. Caroline Garcia, France
7. Elina Svitolina, Ukraine
8. Karolina Pliskova, Czech Republic
9. Julia Goerges, Germany
10. Jelena Ostapenko, Latvia
11. Daria Kasatkina, Russia
12. Garbiñe Muguruza, Spain
13. Kiki Bertens, Netherlands
14. Madison Keys, United States
15. Elise Mertens, Belgium
16. Venus Williams, United States
17. Serena Williams, United States
18. Ashleigh Barty, Australia
19. Anastasija Sevastova, Latvia
20. Naomi Osaka, Japan
21. Mihaela Buzarnescu, Romania
22. Maria Sharapova, Russia
23. Barbora Strycova, Czech Republic
24. CoCo Vandeweghe, United States
25. Daria Gavrilova, Australia
26. Aryna Sabalenka, Belarus
27. Anastasia Pavlyuchenkova, Russia
28. Anett Kontaveit, Estonia
29. Dominika Cibulkova, Slovakia
30. Carla Suarez Navarro, Spain
31. Magdalena Rybarikova, Slovakia
32. Maria Sakkari, Greece
2018 US Open Men’s Singles Seeds
1. Rafael Nadal, Spain
2. Roger Federer, Switzerland
3. Juan Martin del Potro, Argentina
4. Alexander Zverev, Germany
5. Kevin Anderson, South Africa
6. Novak Djokovic, Serbia
7. Marin Cilic, Croatia
8. Grigor Dimitrov, Bulgaria
9. Dominic Thiem, Austria
10. David Goffin, Belgium
11. John Isner, United States
12. Pablo Carreno Busta, Spain
13. Diego Schwartzman, Argentina
14. Fabio Fognini, Italy
15. Stefanos Tsitsipas, Greece
16. Kyle Edmund, Great Britain
17. Lucas Pouille, France
18. Jack Sock, United States
19. Roberto Bautista Agut, Spain
20. Borna Coric, Croatia
21. Kei Nishikori, Japan
22. Marco Cecchinato, Italy
23. Hyeon Chung, South Korea
24. Damir Dzumhur, Bosnia and Herzegovina
25. Milos Raonic, Canada
26. Richard Gasquet, France
27. Karen Khachanov, Russia
28. Denis Shapovalov, Canada
29. Adrian Mannarino, France
30. Nick Kyrgios, Australia
31. Fernando Verdasco, Spain
32. Filip Krajinovic, Serbia
