The 35-year-old, who won 160 caps in a 14-year international career, helped Gotham FC to its first National Women's Soccer League crown last year and said she hopes to spark another NWSL title run by the New York area club before calling it quits.
"It has been one of the greatest joys to represent my country and to wear the US Soccer crest," O'Hara said. "As I close this chapter of my life, I'm filled with gratitude. Looking back on my career I'm so thankful for all the things I was able to accomplish but most importantly the people I was able to accomplish them with."
O'Hara played in four Women's World Cups, the first in 2011, and was a three-time Olympian.
She came off the bench in the 2015 Women's World Cup semi-finals and volleyed a clinching goal against Germany in the semi-finals ahead of a 5-2 triumph over Japan in the final.
At the 2019 Women's World Cup, she started six of seven matches as the Americans captured a fourth title.
O'Hara scored three goals and set up 21 others in 10,287 minutes for the US women.
She played two matches in last year's Women's World Cup and appeared in her final USA match last August against Sweden in San Diego.
