In an interview with Portugal newspaper Expresso, Solo - who has 202 caps - said: "I had Sepp Blatter grab my ass".
"I was in shock and completely thrown off", said Solo.
Solo told The Guardian that she had to compose herself to make a speech before she handed the award to her USA teammate Abby Wambach.
Solo said it came in January of 2013, right before the two went on stage to present an award.
Blatter said thruugh a representaive that the allegations made by Solo were, "ridiculous".
Solo was also asked why she hadn't spoken out about the incident before.
"I speak out directly [with people] when things like that happen".
"I've seen it throughout my entire career and I wish more female athletes would speak out about their own experiences".
'From inappropriate comments, unwanted advances and grabs of the ass to coaches and GMs and even press officers speaking about players "t*ts" and physical appearance, sexual harassment is rampant in the sports world, ' she continued. I didn't get to tell him directly "don't ever touch me".
Last month, Solo posted on Instagram in the wake of revelations about the Hollywood producer Harvey Weinstein, and on Friday she reiterated her stance to the Guardian that more must be done to combat sexual harassment in women's sports. Silence will not change the world! In 2004, he landed in hot water after saying women's soccer should use sex appeal as a way to grow the game.
"For years, in the past, female players date and end up marrying their college coaches, which obviously a coach should not be doing, especially with a young player", she said.
Blatter, 81, was FIFA's president from 1998-2015, but is now serving a six-year ban from any Federation Internationale de Football Association activities after investigations into the corruption of his regime. I've seen it among players in the locker room.