- Hayes, 47, who started her managerial career in the USA, has won 13 major trophies since joining the WSL in 2012.
- "This is a huge honour to be allowed to coach the most incredible team in world football history," Hayes added.
Chelsea boss Emma Hayes has been named the new manager of the United States women's national team and will take charge when the Women's Super League season ends in May.
The Blues announced on Saturday that Hayes would pursue "a new opportunity outside the WSL and club football".
Hayes, 47, who started her managerial career in the USA, has won 13 major trophies since joining the WSL in 2012.
She said her feelings for the US team and the country "run deep".
"This is a huge honour to be allowed to coach the most incredible team in world football history," Hayes added.
"I've dreamed about coaching the USA for a long time so to get this opportunity is a dream come true.
"I know there is work to do to achieve our goals of winning consistently at the highest levels.
"To get there, it will require dedication, devotion and collaboration from the players, staff and everyone at the US Soccer Federation."
Hayes will be the highest-paid women's football coach in the world.
US Soccer president Cindy Parlow called Hayes a "fantastic leader" and a "world-class coach who sets high standards for herself and for everyone around her".
"She has tremendous energy and an insatiable will to win," said Parlow.
"Her experience in the USA, her understanding of our soccer landscape, and her appreciation of what it means to coach this team makes her a natural fit for this role and we could not be more pleased to have her leading our Women's National Team forward."